id stringlengths 24 24 | title stringclasses 442
values | context stringlengths 151 3.71k | question stringlengths 12 270 | answers dict |
|---|---|---|---|---|
572ea9c803f98919007568dc | Neptune | Neptune's orbit has a profound impact on the region directly beyond it, known as the Kuiper belt. The Kuiper belt is a ring of small icy worlds, similar to the asteroid belt but far larger, extending from Neptune's orbit at 30 AU out to about 55 AU from the Sun. Much in the same way that Jupiter's gravity dominates the... | What does the Kuiper belt consist of? | {
"answer_start": [
127
],
"text": [
"small icy worlds"
]
} |
572ea9c803f98919007568dd | Neptune | Neptune's orbit has a profound impact on the region directly beyond it, known as the Kuiper belt. The Kuiper belt is a ring of small icy worlds, similar to the asteroid belt but far larger, extending from Neptune's orbit at 30 AU out to about 55 AU from the Sun. Much in the same way that Jupiter's gravity dominates the... | Where is the Kuiper belt relative to Neptune? | {
"answer_start": [
224
],
"text": [
"30 AU out to about 55 AU from the Sun"
]
} |
572ea9c803f98919007568de | Neptune | Neptune's orbit has a profound impact on the region directly beyond it, known as the Kuiper belt. The Kuiper belt is a ring of small icy worlds, similar to the asteroid belt but far larger, extending from Neptune's orbit at 30 AU out to about 55 AU from the Sun. Much in the same way that Jupiter's gravity dominates the... | What dominates the Kuiper belt? | {
"answer_start": [
362
],
"text": [
"Neptune's gravity"
]
} |
572ea9c803f98919007568df | Neptune | Neptune's orbit has a profound impact on the region directly beyond it, known as the Kuiper belt. The Kuiper belt is a ring of small icy worlds, similar to the asteroid belt but far larger, extending from Neptune's orbit at 30 AU out to about 55 AU from the Sun. Much in the same way that Jupiter's gravity dominates the... | What did Neptune's gravity do to Kuiper belt? | {
"answer_start": [
527
],
"text": [
"gaps in the Kuiper belt's structure"
]
} |
572eaa5903f98919007568e5 | Neptune | There do exist orbits within these empty regions where objects can survive for the age of the Solar System. These resonances occur when Neptune's orbital period is a precise fraction of that of the object, such as 1:2, or 3:4. If, say, an object orbits the Sun once for every two Neptune orbits, it will only complete ha... | What is the fraction of the most heavily populated resonance in the Kuiper belt? | {
"answer_start": [
479
],
"text": [
"2:3 resonance"
]
} |
572eaa5903f98919007568e7 | Neptune | There do exist orbits within these empty regions where objects can survive for the age of the Solar System. These resonances occur when Neptune's orbital period is a precise fraction of that of the object, such as 1:2, or 3:4. If, say, an object orbits the Sun once for every two Neptune orbits, it will only complete ha... | What is the best known, and largest, object in the Kuiper belt? | {
"answer_start": [
673
],
"text": [
"Pluto"
]
} |
572eaa5903f98919007568e6 | Neptune | There do exist orbits within these empty regions where objects can survive for the age of the Solar System. These resonances occur when Neptune's orbital period is a precise fraction of that of the object, such as 1:2, or 3:4. If, say, an object orbits the Sun once for every two Neptune orbits, it will only complete ha... | How many known objects is in the most populated resonance of the Kuiper belt? | {
"answer_start": [
453
],
"text": [
"200"
]
} |
572eaa5903f98919007568e8 | Neptune | There do exist orbits within these empty regions where objects can survive for the age of the Solar System. These resonances occur when Neptune's orbital period is a precise fraction of that of the object, such as 1:2, or 3:4. If, say, an object orbits the Sun once for every two Neptune orbits, it will only complete ha... | What is the resonance of Pluto in the Kuiper belt? | {
"answer_start": [
718
],
"text": [
"2:3"
]
} |
572eaa5903f98919007568e9 | Neptune | There do exist orbits within these empty regions where objects can survive for the age of the Solar System. These resonances occur when Neptune's orbital period is a precise fraction of that of the object, such as 1:2, or 3:4. If, say, an object orbits the Sun once for every two Neptune orbits, it will only complete ha... | Which resonances are less populated in the Kuiper belt? | {
"answer_start": [
768
],
"text": [
"3:4, 3:5, 4:7 and 2:5"
]
} |
572eab33cb0c0d14000f1438 | Neptune | Neptune has a number of known trojan objects occupying both the Sun–Neptune L4 and L5 Lagrangian points—gravitationally stable regions leading and trailing Neptune in its orbit, respectively. Neptune trojans can be viewed as being in a 1:1 resonance with Neptune. Some Neptune trojans are remarkably stable in their orbi... | What is the resonance of Neptune trojans? | {
"answer_start": [
236
],
"text": [
"1:1"
]
} |
572eab33cb0c0d14000f1439 | Neptune | Neptune has a number of known trojan objects occupying both the Sun–Neptune L4 and L5 Lagrangian points—gravitationally stable regions leading and trailing Neptune in its orbit, respectively. Neptune trojans can be viewed as being in a 1:1 resonance with Neptune. Some Neptune trojans are remarkably stable in their orbi... | Where did most Neptune trojans form? | {
"answer_start": [
354
],
"text": [
"alongside Neptune"
]
} |
572eab33cb0c0d14000f143a | Neptune | Neptune has a number of known trojan objects occupying both the Sun–Neptune L4 and L5 Lagrangian points—gravitationally stable regions leading and trailing Neptune in its orbit, respectively. Neptune trojans can be viewed as being in a 1:1 resonance with Neptune. Some Neptune trojans are remarkably stable in their orbi... | What is the only object identified with Neptune's trailing L5 Lagrangian point? | {
"answer_start": [
505
],
"text": [
"2008 LC18"
]
} |
572eab33cb0c0d14000f143b | Neptune | Neptune has a number of known trojan objects occupying both the Sun–Neptune L4 and L5 Lagrangian points—gravitationally stable regions leading and trailing Neptune in its orbit, respectively. Neptune trojans can be viewed as being in a 1:1 resonance with Neptune. Some Neptune trojans are remarkably stable in their orbi... | What is Neptune's temporary quasi-satellite named? | {
"answer_start": [
562
],
"text": [
"(309239) 2007 RW10"
]
} |
572eab33cb0c0d14000f143c | Neptune | Neptune has a number of known trojan objects occupying both the Sun–Neptune L4 and L5 Lagrangian points—gravitationally stable regions leading and trailing Neptune in its orbit, respectively. Neptune trojans can be viewed as being in a 1:1 resonance with Neptune. Some Neptune trojans are remarkably stable in their orbi... | How long has Neptune's quasi-satellite been with Neptune? | {
"answer_start": [
641
],
"text": [
"12,500 years"
]
} |
572ead7cc246551400ce44d8 | Neptune | The formation of the ice giants, Neptune and Uranus, has proven difficult to model precisely. Current models suggest that the matter density in the outer regions of the Solar System was too low to account for the formation of such large bodies from the traditionally accepted method of core accretion, and various hypoth... | What could have blasted Neptune and Uranus's atmosphere with radiation, aiding in creation? | {
"answer_start": [
561
],
"text": [
"nearby massive OB star"
]
} |
572ead7cc246551400ce44d9 | Neptune | The formation of the ice giants, Neptune and Uranus, has proven difficult to model precisely. Current models suggest that the matter density in the outer regions of the Solar System was too low to account for the formation of such large bodies from the traditionally accepted method of core accretion, and various hypoth... | What is too low to account for the formation of Neptune? | {
"answer_start": [
126
],
"text": [
"matter density"
]
} |
572ead7cc246551400ce44da | Neptune | The formation of the ice giants, Neptune and Uranus, has proven difficult to model precisely. Current models suggest that the matter density in the outer regions of the Solar System was too low to account for the formation of such large bodies from the traditionally accepted method of core accretion, and various hypoth... | If Neptune was formed from instabilities within the original protoplanetary disc, what was it not formed by? | {
"answer_start": [
418
],
"text": [
"core accretion"
]
} |
572eae2203f9891900756929 | Neptune | An alternative concept is that they formed closer to the Sun, where the matter density was higher, and then subsequently migrated to their current orbits after the removal of the gaseous protoplanetary disc. This hypothesis of migration after formation is favoured, due to its ability to better explain the occupancy of ... | If Neptune formed closer to the sun, what is the matter density? | {
"answer_start": [
91
],
"text": [
"higher"
]
} |
572eae2203f989190075692a | Neptune | An alternative concept is that they formed closer to the Sun, where the matter density was higher, and then subsequently migrated to their current orbits after the removal of the gaseous protoplanetary disc. This hypothesis of migration after formation is favoured, due to its ability to better explain the occupancy of ... | If Neptune formed closer to the sun, what caused it to migrate to it's current orbit? | {
"answer_start": [
164
],
"text": [
"removal of the gaseous protoplanetary disc"
]
} |
572eae2203f989190075692b | Neptune | An alternative concept is that they formed closer to the Sun, where the matter density was higher, and then subsequently migrated to their current orbits after the removal of the gaseous protoplanetary disc. This hypothesis of migration after formation is favoured, due to its ability to better explain the occupancy of ... | What is the most widely accepted explanation of Neptune's formation called? | {
"answer_start": [
484
],
"text": [
"the Nice model"
]
} |
572eae2203f989190075692c | Neptune | An alternative concept is that they formed closer to the Sun, where the matter density was higher, and then subsequently migrated to their current orbits after the removal of the gaseous protoplanetary disc. This hypothesis of migration after formation is favoured, due to its ability to better explain the occupancy of ... | What does The Nice model consider effected the migration of Neptune? | {
"answer_start": [
601
],
"text": [
"Kuiper belt."
]
} |
572eae88dfa6aa1500f8d2ad | Neptune | Neptune has 14 known moons. Triton is the largest Neptunian moon, comprising more than 99.5% of the mass in orbit around Neptune,[e] and it is the only one massive enough to be spheroidal. Triton was discovered by William Lassell just 17 days after the discovery of Neptune itself. Unlike all other large planetary moons... | How many moons does Neptune have? | {
"answer_start": [
12
],
"text": [
"14"
]
} |
572eae88dfa6aa1500f8d2ae | Neptune | Neptune has 14 known moons. Triton is the largest Neptunian moon, comprising more than 99.5% of the mass in orbit around Neptune,[e] and it is the only one massive enough to be spheroidal. Triton was discovered by William Lassell just 17 days after the discovery of Neptune itself. Unlike all other large planetary moons... | What is Neptune's largest moon? | {
"answer_start": [
28
],
"text": [
"Triton"
]
} |
572eae88dfa6aa1500f8d2af | Neptune | Neptune has 14 known moons. Triton is the largest Neptunian moon, comprising more than 99.5% of the mass in orbit around Neptune,[e] and it is the only one massive enough to be spheroidal. Triton was discovered by William Lassell just 17 days after the discovery of Neptune itself. Unlike all other large planetary moons... | Who discovered Triton? | {
"answer_start": [
214
],
"text": [
"William Lassell"
]
} |
572eae88dfa6aa1500f8d2b0 | Neptune | Neptune has 14 known moons. Triton is the largest Neptunian moon, comprising more than 99.5% of the mass in orbit around Neptune,[e] and it is the only one massive enough to be spheroidal. Triton was discovered by William Lassell just 17 days after the discovery of Neptune itself. Unlike all other large planetary moons... | What orbit does Triton have around Neptune? | {
"answer_start": [
355
],
"text": [
"retrograde orbit"
]
} |
572eae88dfa6aa1500f8d2b1 | Neptune | Neptune has 14 known moons. Triton is the largest Neptunian moon, comprising more than 99.5% of the mass in orbit around Neptune,[e] and it is the only one massive enough to be spheroidal. Triton was discovered by William Lassell just 17 days after the discovery of Neptune itself. Unlike all other large planetary moons... | What does Triton's orbit suggest about it's relation to Neptune? | {
"answer_start": [
384
],
"text": [
"that it was captured"
]
} |
572eaf62cb0c0d14000f147e | Neptune | From July to September 1989, Voyager 2 discovered six moons of Neptune. Of these, the irregularly shaped Proteus is notable for being as large as a body of its density can be without being pulled into a spherical shape by its own gravity. Although the second-most-massive Neptunian moon, it is only 0.25% the mass of Tri... | What discovered six moons of Neptune in 1989? | {
"answer_start": [
29
],
"text": [
"Voyager 2"
]
} |
572eaf62cb0c0d14000f147f | Neptune | From July to September 1989, Voyager 2 discovered six moons of Neptune. Of these, the irregularly shaped Proteus is notable for being as large as a body of its density can be without being pulled into a spherical shape by its own gravity. Although the second-most-massive Neptunian moon, it is only 0.25% the mass of Tri... | What is the second most massive Neptunian moon? | {
"answer_start": [
105
],
"text": [
"Proteus"
]
} |
572eaf62cb0c0d14000f1480 | Neptune | From July to September 1989, Voyager 2 discovered six moons of Neptune. Of these, the irregularly shaped Proteus is notable for being as large as a body of its density can be without being pulled into a spherical shape by its own gravity. Although the second-most-massive Neptunian moon, it is only 0.25% the mass of Tri... | What is notable about the moon Proteus? | {
"answer_start": [
86
],
"text": [
"irregularly shaped"
]
} |
572eaf62cb0c0d14000f1481 | Neptune | From July to September 1989, Voyager 2 discovered six moons of Neptune. Of these, the irregularly shaped Proteus is notable for being as large as a body of its density can be without being pulled into a spherical shape by its own gravity. Although the second-most-massive Neptunian moon, it is only 0.25% the mass of Tri... | Which are Neptune's four innermost moons? | {
"answer_start": [
356
],
"text": [
"Naiad, Thalassa, Despina and Galatea"
]
} |
572eaf62cb0c0d14000f1482 | Neptune | From July to September 1989, Voyager 2 discovered six moons of Neptune. Of these, the irregularly shaped Proteus is notable for being as large as a body of its density can be without being pulled into a spherical shape by its own gravity. Although the second-most-massive Neptunian moon, it is only 0.25% the mass of Tri... | When was Neptune's moon Larissa discovered? | {
"answer_start": [
503
],
"text": [
"1981"
]
} |
572eaff6dfa6aa1500f8d2c9 | Neptune | Because of the distance of Neptune from Earth, its angular diameter only ranges from 2.2 to 2.4 arcseconds, the smallest of the Solar System planets. Its small apparent size makes it challenging to study it visually. Most telescopic data was fairly limited until the advent of Hubble Space Telescope (HST) and large grou... | What is Neptune's angular diameter range? | {
"answer_start": [
85
],
"text": [
"2.2 to 2.4 arcseconds"
]
} |
572eaff6dfa6aa1500f8d2ca | Neptune | Because of the distance of Neptune from Earth, its angular diameter only ranges from 2.2 to 2.4 arcseconds, the smallest of the Solar System planets. Its small apparent size makes it challenging to study it visually. Most telescopic data was fairly limited until the advent of Hubble Space Telescope (HST) and large grou... | The advent of what telescope made it easier to study Neptune? | {
"answer_start": [
277
],
"text": [
"Hubble Space Telescope"
]
} |
572eaff6dfa6aa1500f8d2cb | Neptune | Because of the distance of Neptune from Earth, its angular diameter only ranges from 2.2 to 2.4 arcseconds, the smallest of the Solar System planets. Its small apparent size makes it challenging to study it visually. Most telescopic data was fairly limited until the advent of Hubble Space Telescope (HST) and large grou... | When was the first useful observation of Neptune from the ground? | {
"answer_start": [
491
],
"text": [
"1997"
]
} |
572eaff6dfa6aa1500f8d2cc | Neptune | Because of the distance of Neptune from Earth, its angular diameter only ranges from 2.2 to 2.4 arcseconds, the smallest of the Solar System planets. Its small apparent size makes it challenging to study it visually. Most telescopic data was fairly limited until the advent of Hubble Space Telescope (HST) and large grou... | What seasons are Neptune currently entering? | {
"answer_start": [
543
],
"text": [
"spring and summer"
]
} |
572eaff6dfa6aa1500f8d2cd | Neptune | Because of the distance of Neptune from Earth, its angular diameter only ranges from 2.2 to 2.4 arcseconds, the smallest of the Solar System planets. Its small apparent size makes it challenging to study it visually. Most telescopic data was fairly limited until the advent of Hubble Space Telescope (HST) and large grou... | What was discovered around Neptune in 2004 and 2005? | {
"answer_start": [
1068
],
"text": [
"five new small satellites"
]
} |
572eb077c246551400ce4518 | Neptune | Voyager 2 is the only spacecraft that has visited Neptune. The spacecraft's closest approach to the planet occurred on 25 August 1989. Because this was the last major planet the spacecraft could visit, it was decided to make a close flyby of the moon Triton, regardless of the consequences to the trajectory, similarly t... | What is the only spacecraft to visit Neptune? | {
"answer_start": [
0
],
"text": [
"Voyager 2"
]
} |
572eb077c246551400ce4519 | Neptune | Voyager 2 is the only spacecraft that has visited Neptune. The spacecraft's closest approach to the planet occurred on 25 August 1989. Because this was the last major planet the spacecraft could visit, it was decided to make a close flyby of the moon Triton, regardless of the consequences to the trajectory, similarly t... | When did a spacecraft get closest to Neptune? | {
"answer_start": [
119
],
"text": [
"25 August 1989"
]
} |
572eb077c246551400ce451a | Neptune | Voyager 2 is the only spacecraft that has visited Neptune. The spacecraft's closest approach to the planet occurred on 25 August 1989. Because this was the last major planet the spacecraft could visit, it was decided to make a close flyby of the moon Triton, regardless of the consequences to the trajectory, similarly t... | What near Neptune did a spacecraft visit dangerously close? | {
"answer_start": [
251
],
"text": [
"Triton"
]
} |
572eb077c246551400ce451b | Neptune | Voyager 2 is the only spacecraft that has visited Neptune. The spacecraft's closest approach to the planet occurred on 25 August 1989. Because this was the last major planet the spacecraft could visit, it was decided to make a close flyby of the moon Triton, regardless of the consequences to the trajectory, similarly t... | What program aired on PBS about Neptune? | {
"answer_start": [
492
],
"text": [
"Neptune All Night"
]
} |
572eb0fd03f989190075695f | Neptune | After the Voyager 2 flyby mission, the next step in scientific exploration of the Neptunian system, is considered to be a Flagship orbital mission. Such a hypothetical mission is envisioned to be possible at in the late 2020s or early 2030s. However, there have been a couple of discussions to launch Neptune missions so... | When is the next hypothetical mission to Neptune? | {
"answer_start": [
215
],
"text": [
"late 2020s"
]
} |
572eb0fd03f9891900756960 | Neptune | After the Voyager 2 flyby mission, the next step in scientific exploration of the Neptunian system, is considered to be a Flagship orbital mission. Such a hypothetical mission is envisioned to be possible at in the late 2020s or early 2030s. However, there have been a couple of discussions to launch Neptune missions so... | What about Neptune did NASA propose in 2003 in their "Vision Missions Studies"? | {
"answer_start": [
399
],
"text": [
"Neptune Orbiter with Probes"
]
} |
572eb0fd03f9891900756961 | Neptune | After the Voyager 2 flyby mission, the next step in scientific exploration of the Neptunian system, is considered to be a Flagship orbital mission. Such a hypothetical mission is envisioned to be possible at in the late 2020s or early 2030s. However, there have been a couple of discussions to launch Neptune missions so... | When will Argo be launched? | {
"answer_start": [
550
],
"text": [
"2019"
]
} |
572eb0fd03f9891900756962 | Neptune | After the Voyager 2 flyby mission, the next step in scientific exploration of the Neptunian system, is considered to be a Flagship orbital mission. Such a hypothetical mission is envisioned to be possible at in the late 2020s or early 2030s. However, there have been a couple of discussions to launch Neptune missions so... | What will Argo visit? | {
"answer_start": [
573
],
"text": [
"Jupiter, Saturn, Neptune, and a Kuiper belt object"
]
} |
572eb0fd03f9891900756963 | Neptune | After the Voyager 2 flyby mission, the next step in scientific exploration of the Neptunian system, is considered to be a Flagship orbital mission. Such a hypothetical mission is envisioned to be possible at in the late 2020s or early 2030s. However, there have been a couple of discussions to launch Neptune missions so... | When can we expect Argo to visit Triton? | {
"answer_start": [
709
],
"text": [
"2029"
]
} |
572e8592dfa6aa1500f8d097 | Railway_electrification_system | A railway electrification system supplies electric power to railway trains and trams without an on-board prime mover or local fuel supply. Electrification has many advantages but requires significant capital expenditure. Selection of an electrification system is based on economics of energy supply, maintenance, and cap... | What is of the factors the capital cost of electrification system depends on? | {
"answer_start": [
300
],
"text": [
"maintenance"
]
} |
572e8592dfa6aa1500f8d098 | Railway_electrification_system | A railway electrification system supplies electric power to railway trains and trams without an on-board prime mover or local fuel supply. Electrification has many advantages but requires significant capital expenditure. Selection of an electrification system is based on economics of energy supply, maintenance, and cap... | How do some locomotives function in order to be more flexible in operation? | {
"answer_start": [
482
],
"text": [
"can switch to different supply voltages"
]
} |
572e8592dfa6aa1500f8d09a | Railway_electrification_system | A railway electrification system supplies electric power to railway trains and trams without an on-board prime mover or local fuel supply. Electrification has many advantages but requires significant capital expenditure. Selection of an electrification system is based on economics of energy supply, maintenance, and cap... | What are two types of revenue obtained through railway transportation? | {
"answer_start": [
367
],
"text": [
"freight and passenger traffic"
]
} |
572e8592dfa6aa1500f8d099 | Railway_electrification_system | A railway electrification system supplies electric power to railway trains and trams without an on-board prime mover or local fuel supply. Electrification has many advantages but requires significant capital expenditure. Selection of an electrification system is based on economics of energy supply, maintenance, and cap... | What is the main disadvantage of railway electrification? | {
"answer_start": [
188
],
"text": [
"significant capital expenditure"
]
} |
572e86c1c246551400ce42ca | Railway_electrification_system | Electric railways use electric locomotives to haul passengers or freight in separate cars or electric multiple units, passenger cars with their own motors. Electricity is typically generated in large and relatively efficient generating stations, transmitted to the railway network and distributed to the trains. Some ele... | What is used to haul passengers cars? | {
"answer_start": [
22
],
"text": [
"electric locomotives"
]
} |
572e86c1c246551400ce42cb | Railway_electrification_system | Electric railways use electric locomotives to haul passengers or freight in separate cars or electric multiple units, passenger cars with their own motors. Electricity is typically generated in large and relatively efficient generating stations, transmitted to the railway network and distributed to the trains. Some ele... | How is electricity being generated for electric locomotives? | {
"answer_start": [
225
],
"text": [
"generating stations"
]
} |
572e86c1c246551400ce42cc | Railway_electrification_system | Electric railways use electric locomotives to haul passengers or freight in separate cars or electric multiple units, passenger cars with their own motors. Electricity is typically generated in large and relatively efficient generating stations, transmitted to the railway network and distributed to the trains. Some ele... | What entity provides distribution lines, switches and transformers? | {
"answer_start": [
457
],
"text": [
"railway"
]
} |
572e88f303f9891900756745 | Railway_electrification_system | In comparison to the principal alternative, the diesel engine, electric railways offer substantially better energy efficiency, lower emissions and lower operating costs. Electric locomotives are usually quieter, more powerful, and more responsive and reliable than diesels. They have no local emissions, an important adv... | What is the principal alternative to electric railways? | {
"answer_start": [
48
],
"text": [
"diesel engine"
]
} |
572e88f303f9891900756746 | Railway_electrification_system | In comparison to the principal alternative, the diesel engine, electric railways offer substantially better energy efficiency, lower emissions and lower operating costs. Electric locomotives are usually quieter, more powerful, and more responsive and reliable than diesels. They have no local emissions, an important adv... | What locomotives are usually more reliable? | {
"answer_start": [
170
],
"text": [
"Electric locomotives"
]
} |
572e88f303f9891900756747 | Railway_electrification_system | In comparison to the principal alternative, the diesel engine, electric railways offer substantially better energy efficiency, lower emissions and lower operating costs. Electric locomotives are usually quieter, more powerful, and more responsive and reliable than diesels. They have no local emissions, an important adv... | What do some electric traction systems provide? | {
"answer_start": [
394
],
"text": [
"regenerative braking"
]
} |
572e88f303f9891900756748 | Railway_electrification_system | In comparison to the principal alternative, the diesel engine, electric railways offer substantially better energy efficiency, lower emissions and lower operating costs. Electric locomotives are usually quieter, more powerful, and more responsive and reliable than diesels. They have no local emissions, an important adv... | What type of fuel do diesel locomotives use? | {
"answer_start": [
597
],
"text": [
"petroleum"
]
} |
572e88f303f9891900756749 | Railway_electrification_system | In comparison to the principal alternative, the diesel engine, electric railways offer substantially better energy efficiency, lower emissions and lower operating costs. Electric locomotives are usually quieter, more powerful, and more responsive and reliable than diesels. They have no local emissions, an important adv... | What is one of the sources electricity is being generated from? | {
"answer_start": [
771
],
"text": [
"geothermal"
]
} |
572e8e0fcb0c0d14000f1291 | Railway_electrification_system | Disadvantages of electric traction include high capital costs that may be uneconomic on lightly trafficked routes; a relative lack of flexibility since electric trains need electrified tracks or onboard supercapacitors and charging infrastructure at stations; and a vulnerability to power interruptions. Different region... | What is a safety hazard to track workers? | {
"answer_start": [
519
],
"text": [
"voltages on contact wires"
]
} |
572e8e0fcb0c0d14000f1290 | Railway_electrification_system | Disadvantages of electric traction include high capital costs that may be uneconomic on lightly trafficked routes; a relative lack of flexibility since electric trains need electrified tracks or onboard supercapacitors and charging infrastructure at stations; and a vulnerability to power interruptions. Different region... | What issue can complicate electric railway service? | {
"answer_start": [
330
],
"text": [
"different supply voltages and frequencies,"
]
} |
572e8e0fcb0c0d14000f1292 | Railway_electrification_system | Disadvantages of electric traction include high capital costs that may be uneconomic on lightly trafficked routes; a relative lack of flexibility since electric trains need electrified tracks or onboard supercapacitors and charging infrastructure at stations; and a vulnerability to power interruptions. Different region... | What is a safer alternative to third rails? | {
"answer_start": [
627
],
"text": [
"Overhead wires"
]
} |
572e8e0fcb0c0d14000f1293 | Railway_electrification_system | Disadvantages of electric traction include high capital costs that may be uneconomic on lightly trafficked routes; a relative lack of flexibility since electric trains need electrified tracks or onboard supercapacitors and charging infrastructure at stations; and a vulnerability to power interruptions. Different region... | Why overhead wires are not being widely used? | {
"answer_start": [
689
],
"text": [
"considered unsightly."
]
} |
572e8f7803f98919007567a1 | Railway_electrification_system | Railways must operate at variable speeds. Until the mid 1980s this was only practical with the brush-type DC motor, although such DC can be supplied from an AC catenary via on-board electric power conversion. Since such conversion was not well developed in the late 19th century and early 20th century, most early electr... | What is speed limit for railways? | {
"answer_start": [
25
],
"text": [
"variable speeds"
]
} |
572e8f7803f98919007567a2 | Railway_electrification_system | Railways must operate at variable speeds. Until the mid 1980s this was only practical with the brush-type DC motor, although such DC can be supplied from an AC catenary via on-board electric power conversion. Since such conversion was not well developed in the late 19th century and early 20th century, most early electr... | Why is DC motor being used more than AC type? | {
"answer_start": [
220
],
"text": [
"conversion was not well developed"
]
} |
572e8f7803f98919007567a3 | Railway_electrification_system | Railways must operate at variable speeds. Until the mid 1980s this was only practical with the brush-type DC motor, although such DC can be supplied from an AC catenary via on-board electric power conversion. Since such conversion was not well developed in the late 19th century and early 20th century, most early electr... | What are two types of railway transportation still use DC motor? | {
"answer_start": [
375
],
"text": [
"rapid transit (subways) and trams"
]
} |
572f2607947a6a140053c7dc | Railway_electrification_system | Motors have very little room for electrical insulation so they generally have low voltage ratings. Because transformers (prior to the development of power electronics) cannot step down DC voltages, trains were supplied with a relatively low DC voltage that the motors can use directly. The most common DC voltages are li... | Why do motors have little space for insulation? | {
"answer_start": [
78
],
"text": [
"low voltage ratings"
]
} |
572f2607947a6a140053c7de | Railway_electrification_system | Motors have very little room for electrical insulation so they generally have low voltage ratings. Because transformers (prior to the development of power electronics) cannot step down DC voltages, trains were supplied with a relatively low DC voltage that the motors can use directly. The most common DC voltages are li... | Why 1kV voltage is almost always used by rail systems? | {
"answer_start": [
424
],
"text": [
"safety reasons"
]
} |
572f2607947a6a140053c7dd | Railway_electrification_system | Motors have very little room for electrical insulation so they generally have low voltage ratings. Because transformers (prior to the development of power electronics) cannot step down DC voltages, trains were supplied with a relatively low DC voltage that the motors can use directly. The most common DC voltages are li... | What is most common volatage range used by railway system? | {
"answer_start": [
409
],
"text": [
"below 1 kV"
]
} |
572f2607947a6a140053c7df | Railway_electrification_system | Motors have very little room for electrical insulation so they generally have low voltage ratings. Because transformers (prior to the development of power electronics) cannot step down DC voltages, trains were supplied with a relatively low DC voltage that the motors can use directly. The most common DC voltages are li... | Which system uses higher voltages? | {
"answer_start": [
445
],
"text": [
"overhead wires"
]
} |
572f2607947a6a140053c7e0 | Railway_electrification_system | Motors have very little room for electrical insulation so they generally have low voltage ratings. Because transformers (prior to the development of power electronics) cannot step down DC voltages, trains were supplied with a relatively low DC voltage that the motors can use directly. The most common DC voltages are li... | Is "low" voltage used by trains safe for people? | {
"answer_start": [
560
],
"text": [
"lethal"
]
} |
572f2836b2c2fd1400567f47 | Railway_electrification_system | There has, however, been interest among railroad operators in returning to DC use at higher voltages than previously used. At the same voltage, DC often has less loss than AC, and for this reason high-voltage direct current is already used on some bulk power transmission lines. DC avoids the electromagnetic radiation i... | What type of electric power garantees lesser loss? | {
"answer_start": [
144
],
"text": [
"DC"
]
} |
572f2836b2c2fd1400567f48 | Railway_electrification_system | There has, however, been interest among railroad operators in returning to DC use at higher voltages than previously used. At the same voltage, DC often has less loss than AC, and for this reason high-voltage direct current is already used on some bulk power transmission lines. DC avoids the electromagnetic radiation i... | Which type of supply for electric motors creates electromagnetic radiation? | {
"answer_start": [
172
],
"text": [
"AC"
]
} |
572f2836b2c2fd1400567f4a | Railway_electrification_system | There has, however, been interest among railroad operators in returning to DC use at higher voltages than previously used. At the same voltage, DC often has less loss than AC, and for this reason high-voltage direct current is already used on some bulk power transmission lines. DC avoids the electromagnetic radiation i... | Which type of power does require three-phase transmission? | {
"answer_start": [
632
],
"text": [
"AC"
]
} |
572f2836b2c2fd1400567f49 | Railway_electrification_system | There has, however, been interest among railroad operators in returning to DC use at higher voltages than previously used. At the same voltage, DC often has less loss than AC, and for this reason high-voltage direct current is already used on some bulk power transmission lines. DC avoids the electromagnetic radiation i... | What can electromagnetic radiation interfere with? | {
"answer_start": [
390
],
"text": [
"signalling and communications"
]
} |
572f2836b2c2fd1400567f4b | Railway_electrification_system | There has, however, been interest among railroad operators in returning to DC use at higher voltages than previously used. At the same voltage, DC often has less loss than AC, and for this reason high-voltage direct current is already used on some bulk power transmission lines. DC avoids the electromagnetic radiation i... | Where was an experimental 6kV DC railway built? | {
"answer_start": [
1380
],
"text": [
"the Soviet Union"
]
} |
572f2b31947a6a140053c7e6 | Railway_electrification_system | 1,500 V DC is used in the Netherlands, Japan, Republic Of Indonesia, Hong Kong (parts), Republic of Ireland, Australia (parts), India (around the Mumbai area alone, has been converted to 25 kV AC like the rest of India), France (also using 25 kV 50 Hz AC), New Zealand (Wellington) and the United States (Chicago area on... | What is most common voltage for DC supply? | {
"answer_start": [
0
],
"text": [
"1,500 V"
]
} |
572f2b31947a6a140053c7e7 | Railway_electrification_system | 1,500 V DC is used in the Netherlands, Japan, Republic Of Indonesia, Hong Kong (parts), Republic of Ireland, Australia (parts), India (around the Mumbai area alone, has been converted to 25 kV AC like the rest of India), France (also using 25 kV 50 Hz AC), New Zealand (Wellington) and the United States (Chicago area on... | How many narrow-gauge lines in Slovakia? | {
"answer_start": [
415
],
"text": [
"two"
]
} |
572f2b31947a6a140053c7e8 | Railway_electrification_system | 1,500 V DC is used in the Netherlands, Japan, Republic Of Indonesia, Hong Kong (parts), Republic of Ireland, Australia (parts), India (around the Mumbai area alone, has been converted to 25 kV AC like the rest of India), France (also using 25 kV 50 Hz AC), New Zealand (Wellington) and the United States (Chicago area on... | What railway line is DC being used in Portugal? | {
"answer_start": [
505
],
"text": [
"the Cascais Line"
]
} |
572f2b31947a6a140053c7e9 | Railway_electrification_system | 1,500 V DC is used in the Netherlands, Japan, Republic Of Indonesia, Hong Kong (parts), Republic of Ireland, Australia (parts), India (around the Mumbai area alone, has been converted to 25 kV AC like the rest of India), France (also using 25 kV 50 Hz AC), New Zealand (Wellington) and the United States (Chicago area on... | Where in India line has been converted to AC? | {
"answer_start": [
146
],
"text": [
"Mumbai area"
]
} |
572f2ce3a23a5019007fc4b3 | Railway_electrification_system | 3 kV DC is used in Belgium, Italy, Spain, Poland, the northern Czech Republic, Slovakia, Slovenia, South Africa, Chile, and former Soviet Union countries (also using 25 kV 50 Hz AC). It was formerly used by the Milwaukee Road from Harlowton, Montana to Seattle-Tacoma, across the Continental Divide and including extensi... | What voltage is being used in railway system of South Africa and Chile? | {
"answer_start": [
0
],
"text": [
"3 kV DC"
]
} |
572f2ce3a23a5019007fc4b4 | Railway_electrification_system | 3 kV DC is used in Belgium, Italy, Spain, Poland, the northern Czech Republic, Slovakia, Slovenia, South Africa, Chile, and former Soviet Union countries (also using 25 kV 50 Hz AC). It was formerly used by the Milwaukee Road from Harlowton, Montana to Seattle-Tacoma, across the Continental Divide and including extensi... | Besides using 3kV DC what other power type is used in the former Soviet Union countries? | {
"answer_start": [
166
],
"text": [
"25 kV 50 Hz AC"
]
} |
572f2ce3a23a5019007fc4b5 | Railway_electrification_system | 3 kV DC is used in Belgium, Italy, Spain, Poland, the northern Czech Republic, Slovakia, Slovenia, South Africa, Chile, and former Soviet Union countries (also using 25 kV 50 Hz AC). It was formerly used by the Milwaukee Road from Harlowton, Montana to Seattle-Tacoma, across the Continental Divide and including extensi... | What was New Jersey Transit called before? | {
"answer_start": [
391
],
"text": [
"Western Railroad"
]
} |
572f2ce3a23a5019007fc4b6 | Railway_electrification_system | 3 kV DC is used in Belgium, Italy, Spain, Poland, the northern Czech Republic, Slovakia, Slovenia, South Africa, Chile, and former Soviet Union countries (also using 25 kV 50 Hz AC). It was formerly used by the Milwaukee Road from Harlowton, Montana to Seattle-Tacoma, across the Continental Divide and including extensi... | What does the railway system of US use DC or AC? | {
"answer_start": [
582
],
"text": [
"AC"
]
} |
572f2eff04bcaa1900d76775 | Railway_electrification_system | Most electrification systems use overhead wires, but third rail is an option up to about 1,200 V. Third rail systems exclusively use DC distribution. The use of AC is not feasible because the dimensions of a third rail are physically very large compared with the skin depth that the alternating current penetrates to (0.... | What type is mostly used third rail or overhead wires? | {
"answer_start": [
33
],
"text": [
"overhead wires"
]
} |
572f2eff04bcaa1900d76776 | Railway_electrification_system | Most electrification systems use overhead wires, but third rail is an option up to about 1,200 V. Third rail systems exclusively use DC distribution. The use of AC is not feasible because the dimensions of a third rail are physically very large compared with the skin depth that the alternating current penetrates to (0.... | Is trird rail system being used exclusively with AC or DC ? | {
"answer_start": [
133
],
"text": [
"DC distribution"
]
} |
572f2eff04bcaa1900d76777 | Railway_electrification_system | Most electrification systems use overhead wires, but third rail is an option up to about 1,200 V. Third rail systems exclusively use DC distribution. The use of AC is not feasible because the dimensions of a third rail are physically very large compared with the skin depth that the alternating current penetrates to (0.... | What depth does the alternating current penetrate in a steel rail? | {
"answer_start": [
263
],
"text": [
"skin depth"
]
} |
572f2eff04bcaa1900d76779 | Railway_electrification_system | Most electrification systems use overhead wires, but third rail is an option up to about 1,200 V. Third rail systems exclusively use DC distribution. The use of AC is not feasible because the dimensions of a third rail are physically very large compared with the skin depth that the alternating current penetrates to (0.... | What is more prefferable for subway lines? | {
"answer_start": [
465
],
"text": [
"Third rail"
]
} |
572f2eff04bcaa1900d76778 | Railway_electrification_system | Most electrification systems use overhead wires, but third rail is an option up to about 1,200 V. Third rail systems exclusively use DC distribution. The use of AC is not feasible because the dimensions of a third rail are physically very large compared with the skin depth that the alternating current penetrates to (0.... | What is physically more compact tird rail or overhead wires? | {
"answer_start": [
465
],
"text": [
"Third rail"
]
} |
572f3099a23a5019007fc4c5 | Railway_electrification_system | DC systems (especially third-rail systems) are limited to relatively low voltages and this can limit the size and speed of trains and cannot use low-level platform and also limit the amount of air-conditioning that the trains can provide. This may be a factor favouring overhead wires and high-voltage AC, even for urban... | Why DC system can effect the speed of trains? | {
"answer_start": [
69
],
"text": [
"low voltages"
]
} |
572f3099a23a5019007fc4c6 | Railway_electrification_system | DC systems (especially third-rail systems) are limited to relatively low voltages and this can limit the size and speed of trains and cannot use low-level platform and also limit the amount of air-conditioning that the trains can provide. This may be a factor favouring overhead wires and high-voltage AC, even for urban... | Can DC systems use low-level platform? | {
"answer_start": [
134
],
"text": [
"cannot"
]
} |
572f3099a23a5019007fc4c7 | Railway_electrification_system | DC systems (especially third-rail systems) are limited to relatively low voltages and this can limit the size and speed of trains and cannot use low-level platform and also limit the amount of air-conditioning that the trains can provide. This may be a factor favouring overhead wires and high-voltage AC, even for urban... | Besides speed and size what else the low voltage of DC system can effect? | {
"answer_start": [
193
],
"text": [
"air-conditioning"
]
} |
572f3099a23a5019007fc4c8 | Railway_electrification_system | DC systems (especially third-rail systems) are limited to relatively low voltages and this can limit the size and speed of trains and cannot use low-level platform and also limit the amount of air-conditioning that the trains can provide. This may be a factor favouring overhead wires and high-voltage AC, even for urban... | What is the speed limit for third rail system trains? | {
"answer_start": [
410
],
"text": [
"160 km/h"
]
} |
572f3099a23a5019007fc4c9 | Railway_electrification_system | DC systems (especially third-rail systems) are limited to relatively low voltages and this can limit the size and speed of trains and cannot use low-level platform and also limit the amount of air-conditioning that the trains can provide. This may be a factor favouring overhead wires and high-voltage AC, even for urban... | What can become unreliable if the speed exceeds the limit of 100 mph for DC system trains? | {
"answer_start": [
454
],
"text": [
"contact between the shoe and the rail"
]
} |
572f3315b2c2fd1400567f77 | Railway_electrification_system | Some street trams (streetcars) used conduit third-rail current collection. The third rail was below street level. The tram picked up the current through a plough (U.S. "plow") accessed through a narrow slot in the road. In the United States, much (though not all) of the former streetcar system in Washington, D.C. (disc... | What is the other name for the street trams? | {
"answer_start": [
19
],
"text": [
"streetcars"
]
} |
572f3315b2c2fd1400567f78 | Railway_electrification_system | Some street trams (streetcars) used conduit third-rail current collection. The third rail was below street level. The tram picked up the current through a plough (U.S. "plow") accessed through a narrow slot in the road. In the United States, much (though not all) of the former streetcar system in Washington, D.C. (disc... | Where is third rail situated in the street trams system? | {
"answer_start": [
94
],
"text": [
"below street level"
]
} |
572f3315b2c2fd1400567f79 | Railway_electrification_system | Some street trams (streetcars) used conduit third-rail current collection. The third rail was below street level. The tram picked up the current through a plough (U.S. "plow") accessed through a narrow slot in the road. In the United States, much (though not all) of the former streetcar system in Washington, D.C. (disc... | What area in US discontinued using overhead wires for streetcars in 1962? | {
"answer_start": [
298
],
"text": [
"Washington, D.C."
]
} |
572f3315b2c2fd1400567f7a | Railway_electrification_system | Some street trams (streetcars) used conduit third-rail current collection. The third rail was below street level. The tram picked up the current through a plough (U.S. "plow") accessed through a narrow slot in the road. In the United States, much (though not all) of the former streetcar system in Washington, D.C. (disc... | What external and weather factors can effect conduit slot? | {
"answer_start": [
1171
],
"text": [
"leaves and snow"
]
} |
572f3315b2c2fd1400567f7b | Railway_electrification_system | Some street trams (streetcars) used conduit third-rail current collection. The third rail was below street level. The tram picked up the current through a plough (U.S. "plow") accessed through a narrow slot in the road. In the United States, much (though not all) of the former streetcar system in Washington, D.C. (disc... | What are the main reasons the conduit lines were converted to overhead wire system? | {
"answer_start": [
1507
],
"text": [
"cost and operating efficiency"
]
} |
572f3f3404bcaa1900d767c5 | Railway_electrification_system | A new approach to avoiding overhead wires is taken by the "second generation" tram/streetcar system in Bordeaux, France (entry into service of the first line in December 2003; original system discontinued in 1958) with its APS (alimentation par sol – ground current feed). This involves a third rail which is flush with ... | What year the "second generation" of tram system began to operate in France? | {
"answer_start": [
170
],
"text": [
"2003"
]
} |
572f3f3404bcaa1900d767c6 | Railway_electrification_system | A new approach to avoiding overhead wires is taken by the "second generation" tram/streetcar system in Bordeaux, France (entry into service of the first line in December 2003; original system discontinued in 1958) with its APS (alimentation par sol – ground current feed). This involves a third rail which is flush with ... | When was the original system discontinued? | {
"answer_start": [
208
],
"text": [
"1958"
]
} |
572f3f3404bcaa1900d767c7 | Railway_electrification_system | A new approach to avoiding overhead wires is taken by the "second generation" tram/streetcar system in Bordeaux, France (entry into service of the first line in December 2003; original system discontinued in 1958) with its APS (alimentation par sol – ground current feed). This involves a third rail which is flush with ... | How is the circuit of the third rail divided? | {
"answer_start": [
548
],
"text": [
"energized segment"
]
} |
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