answer string | choices dict | id string | kind string | lang string | question string | steps list | subject string | text string | topic string |
|---|---|---|---|---|---|---|---|---|---|
Waves spread past edges, letting sound turn corners. | null | phy_0701 | concept | en | How does diffraction turn corners? | [
"Waves spread past edges, letting sound turn corners.",
"So the answer stands: Waves spread past edges, letting sound turn corners."
] | physics | Answer: Waves spread past edges, letting sound turn corners.
Steps:
1. Waves spread past edges, letting sound turn corners.
2. So the answer stands: Waves spread past edges, letting sound turn corners. | waves |
Annihilation photons pinpoint tracers inside bodies precisely. | null | phy_0702 | concept | en | Why PET scans? | [
"Annihilation photons pinpoint tracers inside bodies precisely.",
"So the answer stands: Annihilation photons pinpoint tracers inside bodies precisely."
] | physics | Answer: Annihilation photons pinpoint tracers inside bodies precisely.
Steps:
1. Annihilation photons pinpoint tracers inside bodies precisely.
2. So the answer stands: Annihilation photons pinpoint tracers inside bodies precisely. | modern |
Momentum: 48 kg·m/s. | null | phy_0703 | worked_example | en | A mass of 16 kg moves at 3 m/s. Compute its momentum. | [
"p = m×v.",
"p = 16 kg × 3 m/s.",
"= 48 kg·m/s."
] | physics | Answer: Momentum: 48 kg·m/s.
Steps:
1. p = m×v.
2. p = 16 kg × 3 m/s.
3. = 48 kg·m/s. | mechanics |
Tiny gates switch big currents, amplifying signals into computers. | null | phy_0704 | concept | en | What is a transistor? | [
"Tiny gates switch big currents, amplifying signals into computers.",
"So the answer stands: Tiny gates switch big currents, amplifying signals into computers."
] | physics | Answer: Tiny gates switch big currents, amplifying signals into computers.
Steps:
1. Tiny gates switch big currents, amplifying signals into computers.
2. So the answer stands: Tiny gates switch big currents, amplifying signals into computers. | electromagnetism |
Temperature: 301 K. | null | phy_0705 | worked_example | en | Temperature is 28 °C. Convert it to kelvin. | [
"Add 273.",
"28 + 273.",
"= 301 K."
] | physics | Answer: Temperature: 301 K.
Steps:
1. Add 273.
2. 28 + 273.
3. = 301 K. | thermodynamics |
Zdánlivá hloubka je 30 cm. | {
"A": "25 cm",
"B": "35 cm",
"C": "40 cm",
"D": "30 cm"
} | phy_0706 | multiple_choice | cs | Předmět leží 45 cm hluboko ve skle (n = 1,5). Jaká je zdánlivá hloubka? | [
"d' = 45 cm / 1,5.",
"d' = 30 cm.",
"Vyber možnost D."
] | physics | Answer: 30 cm
Steps:
1. d' = 45 cm / 1,5.
2. d' = 30 cm.
3. Vyber možnost D.
Answer: (D) | optics |
Pipes channel microwaves efficiently to antennas and ovens. | null | phy_0707 | concept | en | Why waveguides? | [
"Pipes channel microwaves efficiently to antennas and ovens.",
"So the answer stands: Pipes channel microwaves efficiently to antennas and ovens."
] | physics | Answer: Pipes channel microwaves efficiently to antennas and ovens.
Steps:
1. Pipes channel microwaves efficiently to antennas and ovens.
2. So the answer stands: Pipes channel microwaves efficiently to antennas and ovens. | waves |
Odpověď je pohybující se hodiny. | {
"A": "pohybující se hodiny",
"B": "rozbité hodinky",
"C": "zastavené minutky",
"D": "ztracené telefony"
} | phy_0708 | multiple_choice | cs | Vyber: co tiká pomaleji? | [
"Miony potvrzují.",
"Tedy: pohybující se hodiny.",
"Vyber možnost A."
] | physics | Answer: pohybující se hodiny
Steps:
1. Miony potvrzují.
2. Tedy: pohybující se hodiny.
3. Vyber možnost A.
Answer: (A) | modern |
Hybnost mv přetrvává srážkami. | null | phy_0709 | concept | cs | Co je hybnost? | [
"Hybnost mv přetrvává srážkami.",
"Odpověď tedy platí: Hybnost mv přetrvává srážkami."
] | physics | Answer: Hybnost mv přetrvává srážkami.
Steps:
1. Hybnost mv přetrvává srážkami.
2. Odpověď tedy platí: Hybnost mv přetrvává srážkami. | mechanics |
Voltage: 168 V. | null | phy_0710 | worked_example | en | A current of 14 A flows through 12 Ω. Compute the voltage. | [
"V = I×R.",
"V = 14 A × 12 Ω.",
"= 168 V."
] | physics | Answer: Voltage: 168 V.
Steps:
1. V = I×R.
2. V = 14 A × 12 Ω.
3. = 168 V. | electromagnetism |
Efficiency is 70%. | {
"A": "60%",
"B": "80%",
"C": "90%",
"D": "70%"
} | phy_0711 | multiple_choice | en | An engine turns 700 J of 1000 J heat into work. What is its efficiency? | [
"700 J / 1000 J.",
"= 70%.",
"Select option D."
] | physics | Answer: 70%
Steps:
1. 700 J / 1000 J.
2. = 70%.
3. Select option D.
Answer: (D) | thermodynamics |
Time is 7 s. | {
"A": "8 s",
"B": "9 s",
"C": "6 s",
"D": "7 s"
} | phy_0712 | multiple_choice | en | Light travels 21×10⁸ m. How many seconds does it take? (c = 3×10⁸ m/s) | [
"t = 21×10⁸ m / 3×10⁸ m/s.",
"t = 7 s.",
"Select option D."
] | physics | Answer: 7 s
Steps:
1. t = 21×10⁸ m / 3×10⁸ m/s.
2. t = 7 s.
3. Select option D.
Answer: (D) | optics |
Odpověď je v rovná se fλ. | {
"A": "v rovná se fλ",
"B": "E rovná se mc",
"C": "F rovná se ma",
"D": "pV rovná se nRT"
} | phy_0713 | multiple_choice | cs | Vyber: co váže rychlost a cykly? | [
"Hlavní vztah držen.",
"Tedy: v rovná se fλ.",
"Vyber možnost A."
] | physics | Answer: v rovná se fλ
Steps:
1. Hlavní vztah držen.
2. Tedy: v rovná se fλ.
3. Vyber možnost A.
Answer: (A) | waves |
Survivors: 2800. | null | phy_0714 | worked_example | en | A sample of 11200 atoms undergoes 2 half-lives. Compute the survivors. | [
"Halve: 11200 → 5600.",
"Halve: 5600 → 2800.",
"= 2800."
] | physics | Answer: Survivors: 2800.
Steps:
1. Halve: 11200 → 5600.
2. Halve: 5600 → 2800.
3. = 2800. | modern |
Net force: 30 N. | null | phy_0715 | worked_example | en | A mass of 15 kg accelerates at 2 m/s². Compute the net force. | [
"F = m×a.",
"F = 15 kg × 2 m/s².",
"= 30 N."
] | physics | Answer: Net force: 30 N.
Steps:
1. F = m×a.
2. F = 15 kg × 2 m/s².
3. = 30 N. | mechanics |
Energy: 1800 J. | null | phy_0716 | worked_example | en | A 100 W heater runs for 18 s. Compute the energy used. | [
"E = P×t.",
"E = 100 W × 18 s.",
"= 1800 J."
] | physics | Answer: Energy: 1800 J.
Steps:
1. E = P×t.
2. E = 100 W × 18 s.
3. = 1800 J. | electromagnetism |
Insulated mixing reveals unknown heats by balancing lost and gained energy. | null | phy_0717 | concept | en | Why calorimetry? | [
"Insulated mixing reveals unknown heats by balancing lost and gained energy.",
"So the answer stands: Insulated mixing reveals unknown heats by balancing lost and gained energy."
] | physics | Answer: Insulated mixing reveals unknown heats by balancing lost and gained energy.
Steps:
1. Insulated mixing reveals unknown heats by balancing lost and gained energy.
2. So the answer stands: Insulated mixing reveals unknown heats by balancing lost and gained energy. | thermodynamics |
Magnification: 15×. | null | phy_0718 | worked_example | en | An image forms 150 cm from a lens, object at 10 cm. Compute the magnification. | [
"M = di/do.",
"M = 150 cm / 10 cm.",
"= 15×."
] | physics | Answer: Magnification: 15×.
Steps:
1. M = di/do.
2. M = 150 cm / 10 cm.
3. = 15×. | optics |
Long ocean waves race at jet speed with huge energy. | null | phy_0719 | concept | en | What is a tsunami? | [
"Long ocean waves race at jet speed with huge energy.",
"So the answer stands: Long ocean waves race at jet speed with huge energy."
] | physics | Answer: Long ocean waves race at jet speed with huge energy.
Steps:
1. Long ocean waves race at jet speed with huge energy.
2. So the answer stands: Long ocean waves race at jet speed with huge energy. | waves |
Paired electrons flow losslessly below critical cold. | null | phy_0720 | concept | en | What is superconductivity? | [
"Paired electrons flow losslessly below critical cold.",
"So the answer stands: Paired electrons flow losslessly below critical cold."
] | physics | Answer: Paired electrons flow losslessly below critical cold.
Steps:
1. Paired electrons flow losslessly below critical cold.
2. So the answer stands: Paired electrons flow losslessly below critical cold. | modern |
Speed is 16 m/s. | {
"A": "15 m/s",
"B": "17 m/s",
"C": "18 m/s",
"D": "16 m/s"
} | phy_0721 | multiple_choice | en | A car travels 160 m in 10 s. What is its speed? | [
"v = 160 m / 10 s.",
"v = 16 m/s.",
"Select option D."
] | physics | Answer: 16 m/s
Steps:
1. v = 160 m / 10 s.
2. v = 16 m/s.
3. Select option D.
Answer: (D) | mechanics |
Power is 96 W. | {
"A": "84 W",
"B": "108 W",
"C": "96 W",
"D": "120 W"
} | phy_0722 | multiple_choice | en | A bulb runs at 12 V drawing 8 A. What is its power? | [
"P = 12 V × 8 A.",
"P = 96 W.",
"Select option C."
] | physics | Answer: 96 W
Steps:
1. P = 12 V × 8 A.
2. P = 96 W.
3. Select option C.
Answer: (C) | electromagnetism |
Heat: 117208 J. | null | phy_0723 | worked_example | en | How much heat warms 2 kg of water by 14 K? (c = 4186 J/(kg·K)) | [
"Q = 2 kg × 4186 J/(kg·K) × 14 K.",
"= 117208 J."
] | physics | Answer: Heat: 117208 J.
Steps:
1. Q = 2 kg × 4186 J/(kg·K) × 14 K.
2. = 117208 J. | thermodynamics |
It marks when two spots just separate, timing optics precisely. | null | phy_0724 | concept | en | Why Rayleigh criterion? | [
"It marks when two spots just separate, timing optics precisely.",
"So the answer stands: It marks when two spots just separate, timing optics precisely."
] | physics | Answer: It marks when two spots just separate, timing optics precisely.
Steps:
1. It marks when two spots just separate, timing optics precisely.
2. So the answer stands: It marks when two spots just separate, timing optics precisely. | optics |
Speed: 2550 m/s. | null | phy_0725 | worked_example | en | A string wave has f = 850 Hz and λ = 3 m. Compute its speed. | [
"v = f×λ.",
"v = 850 Hz × 3 m.",
"= 2550 m/s."
] | physics | Answer: Speed: 2550 m/s.
Steps:
1. v = f×λ.
2. v = 850 Hz × 3 m.
3. = 2550 m/s. | waves |
Superposed qubits explore many paths at once for select tasks. | null | phy_0726 | concept | en | Why quantum computers? | [
"Superposed qubits explore many paths at once for select tasks.",
"So the answer stands: Superposed qubits explore many paths at once for select tasks."
] | physics | Answer: Superposed qubits explore many paths at once for select tasks.
Steps:
1. Superposed qubits explore many paths at once for select tasks.
2. So the answer stands: Superposed qubits explore many paths at once for select tasks. | modern |
Small swings take 2π√(L/g), depending on length, not on mass or amplitude. | null | phy_0727 | concept | en | What is a pendulum's period? | [
"Small swings take 2π√(L/g), depending on length, not on mass or amplitude.",
"So the answer stands: Small swings take 2π√(L/g), depending on length, not on mass or amplitude."
] | physics | Answer: Small swings take 2π√(L/g), depending on length, not on mass or amplitude.
Steps:
1. Small swings take 2π√(L/g), depending on length, not on mass or amplitude.
2. So the answer stands: Small swings take 2π√(L/g), depending on length, not on mass or amplitude. | mechanics |
Charge is 140 C. | {
"A": "120 C",
"B": "160 C",
"C": "180 C",
"D": "140 C"
} | phy_0728 | multiple_choice | en | A current of 4 A flows for 35 s. How much charge passes? | [
"Q = 4 A × 35 s.",
"Q = 140 C.",
"Select option D."
] | physics | Answer: 140 C
Steps:
1. Q = 4 A × 35 s.
2. Q = 140 C.
3. Select option D.
Answer: (D) | electromagnetism |
Temperature is 299 K. | {
"A": "298 K",
"B": "300 K",
"C": "299 K",
"D": "301 K"
} | phy_0729 | multiple_choice | en | Room temperature is 26 °C. What is it in kelvin? | [
"26 °C + 273.",
"= 299 K.",
"Select option C."
] | physics | Answer: 299 K
Steps:
1. 26 °C + 273.
2. = 299 K.
3. Select option C.
Answer: (C) | thermodynamics |
Time: 13.3 s. | null | phy_0730 | worked_example | en | Light travels 40×10⁸ m. Compute the travel time. (c = 3×10⁸ m/s) | [
"t = d/c.",
"t = 40×10⁸ / 3×10⁸ s.",
"= 13.3 s."
] | physics | Answer: Time: 13.3 s.
Steps:
1. t = d/c.
2. t = 40×10⁸ / 3×10⁸ s.
3. = 13.3 s. | optics |
Odpověď je decibel. | {
"A": "metr",
"B": "decibel",
"C": "sekunda",
"D": "gram"
} | phy_0731 | multiple_choice | cs | Vyber: co logaritmuje hlasitost? | [
"Výkon poměřen.",
"Tedy: decibel.",
"Vyber možnost B."
] | physics | Answer: decibel
Steps:
1. Výkon poměřen.
2. Tedy: decibel.
3. Vyber možnost B.
Answer: (B) | waves |
Lines: 136. | null | phy_0732 | worked_example | en | An atom is excited to level n = 17. Count the spectral lines it can emit. | [
"Pairs: 17×16/2.",
"= 272/2.",
"= 136."
] | physics | Answer: Lines: 136.
Steps:
1. Pairs: 17×16/2.
2. = 272/2.
3. = 136. | modern |
Driving at natural frequency pumps amplitude hugely, shattering glasses and bridges. | null | phy_0733 | concept | en | Why resonance? | [
"Driving at natural frequency pumps amplitude hugely, shattering glasses and bridges.",
"So the answer stands: Driving at natural frequency pumps amplitude hugely, shattering glasses and bridges."
] | physics | Answer: Driving at natural frequency pumps amplitude hugely, shattering glasses and bridges.
Steps:
1. Driving at natural frequency pumps amplitude hugely, shattering glasses and bridges.
2. So the answer stands: Driving at natural frequency pumps amplitude hugely, shattering glasses and bridges. | mechanics |
Srážky uvnitř vodičů brání driftu. | null | phy_0734 | concept | cs | Proč odpor? | [
"Srážky uvnitř vodičů brání driftu.",
"Odpověď tedy platí: Srážky uvnitř vodičů brání driftu."
] | physics | Answer: Srážky uvnitř vodičů brání driftu.
Steps:
1. Srážky uvnitř vodičů brání driftu.
2. Odpověď tedy platí: Srážky uvnitř vodičů brání driftu. | electromagnetism |
It rates heat flow per gradient, high in copper, low in wool. | null | phy_0735 | concept | en | What is thermal conductivity? | [
"It rates heat flow per gradient, high in copper, low in wool.",
"So the answer stands: It rates heat flow per gradient, high in copper, low in wool."
] | physics | Answer: It rates heat flow per gradient, high in copper, low in wool.
Steps:
1. It rates heat flow per gradient, high in copper, low in wool.
2. So the answer stands: It rates heat flow per gradient, high in copper, low in wool. | thermodynamics |
Apparent depth is 80 cm. | {
"A": "80 cm",
"B": "75 cm",
"C": "85 cm",
"D": "90 cm"
} | phy_0736 | multiple_choice | en | An object sits 120 cm deep in glass (n = 1.5). What is the apparent depth? | [
"d' = 120 cm / 1.5.",
"d' = 80 cm.",
"Select option A."
] | physics | Answer: 80 cm
Steps:
1. d' = 120 cm / 1.5.
2. d' = 80 cm.
3. Select option A.
Answer: (A) | optics |
Distance: 5100 m. | null | phy_0737 | worked_example | en | Thunder is heard 15 s after lightning. How far away is the storm? (v = 340 m/s) | [
"d = v×t.",
"d = 340 m/s × 15 s.",
"= 5100 m."
] | physics | Answer: Distance: 5100 m.
Steps:
1. d = v×t.
2. d = 340 m/s × 15 s.
3. = 5100 m. | waves |
The answer is Pauli fermions. | {
"A": "Pauli fermions",
"B": "Chatty neighbours",
"C": "Noisy crowds",
"D": "Busy bees"
} | phy_0738 | multiple_choice | en | Choose: what shares no state? | [
"Table built.",
"So: Pauli fermions.",
"Select option A."
] | physics | Answer: Pauli fermions
Steps:
1. Table built.
2. So: Pauli fermions.
3. Select option A.
Answer: (A) | modern |
Kinetic energy is 100 J. | {
"A": "100 J",
"B": "90 J",
"C": "110 J",
"D": "120 J"
} | phy_0739 | multiple_choice | en | A 2 kg ball moves at 10 m/s. What is its kinetic energy? | [
"KE = ½×2 kg×(10 m/s)².",
"KE = 100 J.",
"Select option A."
] | physics | Answer: 100 J
Steps:
1. KE = ½×2 kg×(10 m/s)².
2. KE = 100 J.
3. Select option A.
Answer: (A) | mechanics |
Zero resistance below critical temperature carries current forever losslessly. | null | phy_0740 | concept | en | Why superconductors? | [
"Zero resistance below critical temperature carries current forever losslessly.",
"So the answer stands: Zero resistance below critical temperature carries current forever losslessly."
] | physics | Answer: Zero resistance below critical temperature carries current forever losslessly.
Steps:
1. Zero resistance below critical temperature carries current forever losslessly.
2. So the answer stands: Zero resistance below critical temperature carries current forever losslessly. | electromagnetism |
Teplota: 291 K. | null | phy_0741 | worked_example | cs | Teplota je 18 °C. Převeď ji na kelviny. | [
"Přičti 273.",
"18 + 273.",
"= 291 K."
] | physics | Answer: Teplota: 291 K.
Steps:
1. Přičti 273.
2. 18 + 273.
3. = 291 K. | thermodynamics |
Stimulated emission makes coherent intense beams, cutting and reading precisely. | null | phy_0742 | concept | en | What is a laser? | [
"Stimulated emission makes coherent intense beams, cutting and reading precisely.",
"So the answer stands: Stimulated emission makes coherent intense beams, cutting and reading precisely."
] | physics | Answer: Stimulated emission makes coherent intense beams, cutting and reading precisely.
Steps:
1. Stimulated emission makes coherent intense beams, cutting and reading precisely.
2. So the answer stands: Stimulated emission makes coherent intense beams, cutting and reading precisely. | optics |
3rd harmonic is 480 Hz. | {
"A": "450 Hz",
"B": "510 Hz",
"C": "540 Hz",
"D": "480 Hz"
} | phy_0743 | multiple_choice | en | A string's fundamental is 160 Hz. What is its 3rd harmonic? | [
"f3 = 3 × 160 Hz.",
"f3 = 480 Hz.",
"Select option D."
] | physics | Answer: 480 Hz
Steps:
1. f3 = 3 × 160 Hz.
2. f3 = 480 Hz.
3. Select option D.
Answer: (D) | waves |
600 atoms remain. | {
"A": "550",
"B": "600",
"C": "650",
"D": "700"
} | phy_0744 | multiple_choice | en | A sample of 2400 atoms undergoes 2 half-lives. How many remain? | [
"Halve twice: 2400 → 1200 → 600.",
"Left: 600.",
"Select option B."
] | physics | Answer: 600
Steps:
1. Halve twice: 2400 → 1200 → 600.
2. Left: 600.
3. Select option B.
Answer: (B) | modern |
Net force is 27 N. | {
"A": "24 N",
"B": "30 N",
"C": "33 N",
"D": "27 N"
} | phy_0745 | multiple_choice | en | A mass of 9 kg accelerates at 3 m/s². What is the net force? | [
"F = 9 kg × 3 m/s².",
"F = 27 N.",
"Select option D."
] | physics | Answer: 27 N
Steps:
1. F = 9 kg × 3 m/s².
2. F = 27 N.
3. Select option D.
Answer: (D) | mechanics |
Voltage is 40 V. | {
"A": "35 V",
"B": "45 V",
"C": "40 V",
"D": "50 V"
} | phy_0746 | multiple_choice | en | A current of 8 A flows through 5 Ω. What is the voltage? | [
"V = 8 A × 5 Ω.",
"V = 40 V.",
"Select option C."
] | physics | Answer: 40 V
Steps:
1. V = 8 A × 5 Ω.
2. V = 40 V.
3. Select option C.
Answer: (C) | electromagnetism |
Odpověď je Carnotova mez. | {
"A": "rychlostní limit",
"B": "Carnotova mez",
"C": "váhový limit",
"D": "věkový limit"
} | phy_0747 | multiple_choice | cs | Vyber: co stropuje všechny stroje? | [
"Poměr teplot váže.",
"Tedy: Carnotova mez.",
"Vyber možnost B."
] | physics | Answer: Carnotova mez
Steps:
1. Poměr teplot váže.
2. Tedy: Carnotova mez.
3. Vyber možnost B.
Answer: (B) | thermodynamics |
Apparent depth: 150 cm. | null | phy_0748 | worked_example | en | An object sits 225 cm deep in glass (n = 1.5). Compute the apparent depth. | [
"d' = d/n.",
"d' = 225 cm / 1.5.",
"= 150 cm."
] | physics | Answer: Apparent depth: 150 cm.
Steps:
1. d' = d/n.
2. d' = 225 cm / 1.5.
3. = 150 cm. | optics |
Speed is 800 m/s. | {
"A": "750 m/s",
"B": "850 m/s",
"C": "800 m/s",
"D": "900 m/s"
} | phy_0749 | multiple_choice | en | A string wave has f = 400 Hz and λ = 2 m. What is its speed? | [
"v = 400 Hz × 2 m.",
"v = 800 m/s.",
"Select option C."
] | physics | Answer: 800 m/s
Steps:
1. v = 400 Hz × 2 m.
2. v = 800 m/s.
3. Select option C.
Answer: (C) | waves |
Mikrosvět se řídí vlnovými pravidly. | null | phy_0750 | concept | cs | Co je kvantová mechanika? | [
"Mikrosvět se řídí vlnovými pravidly.",
"Odpověď tedy platí: Mikrosvět se řídí vlnovými pravidly."
] | physics | Answer: Mikrosvět se řídí vlnovými pravidly.
Steps:
1. Mikrosvět se řídí vlnovými pravidly.
2. Odpověď tedy platí: Mikrosvět se řídí vlnovými pravidly. | modern |
Speed is 17 m/s. | {
"A": "17 m/s",
"B": "16 m/s",
"C": "18 m/s",
"D": "19 m/s"
} | phy_0751 | multiple_choice | en | A car travels 170 m in 10 s. What is its speed? | [
"v = 170 m / 10 s.",
"v = 17 m/s.",
"Select option A."
] | physics | Answer: 17 m/s
Steps:
1. v = 170 m / 10 s.
2. v = 17 m/s.
3. Select option A.
Answer: (A) | mechanics |
Sideways voltage reveals charge sign and density in conductors. | null | phy_0752 | concept | en | What is Hall effect? | [
"Sideways voltage reveals charge sign and density in conductors.",
"So the answer stands: Sideways voltage reveals charge sign and density in conductors."
] | physics | Answer: Sideways voltage reveals charge sign and density in conductors.
Steps:
1. Sideways voltage reveals charge sign and density in conductors.
2. So the answer stands: Sideways voltage reveals charge sign and density in conductors. | electromagnetism |
Trapped air slows conduction and convection, keeping houses warm cheaply. | null | phy_0753 | concept | en | Why insulation? | [
"Trapped air slows conduction and convection, keeping houses warm cheaply.",
"So the answer stands: Trapped air slows conduction and convection, keeping houses warm cheaply."
] | physics | Answer: Trapped air slows conduction and convection, keeping houses warm cheaply.
Steps:
1. Trapped air slows conduction and convection, keeping houses warm cheaply.
2. So the answer stands: Trapped air slows conduction and convection, keeping houses warm cheaply. | thermodynamics |
Magnification: 16×. | null | phy_0754 | worked_example | en | An image forms 160 cm from a lens, object at 10 cm. Compute the magnification. | [
"M = di/do.",
"M = 160 cm / 10 cm.",
"= 16×."
] | physics | Answer: Magnification: 16×.
Steps:
1. M = di/do.
2. M = 160 cm / 10 cm.
3. = 16×. | optics |
Tides are slow gravitational sloshes, not wind-driven waves. | null | phy_0755 | concept | en | Why tides differ? | [
"Tides are slow gravitational sloshes, not wind-driven waves.",
"So the answer stands: Tides are slow gravitational sloshes, not wind-driven waves."
] | physics | Answer: Tides are slow gravitational sloshes, not wind-driven waves.
Steps:
1. Tides are slow gravitational sloshes, not wind-driven waves.
2. So the answer stands: Tides are slow gravitational sloshes, not wind-driven waves. | waves |
Čar: 21. | null | phy_0756 | worked_example | cs | Atom je vybuzen do hladiny n = 7. Spočítej čáry, jež může vyzářit. | [
"Dvojice: 7×6/2.",
"= 42/2.",
"= 21."
] | physics | Answer: Čar: 21.
Steps:
1. Dvojice: 7×6/2.
2. = 42/2.
3. = 21. | modern |
Work: 280 J. | null | phy_0757 | worked_example | en | A force of 70 N pushes 4 m. Compute the work done. | [
"W = F×d.",
"W = 70 N × 4 m.",
"= 280 J."
] | physics | Answer: Work: 280 J.
Steps:
1. W = F×d.
2. W = 70 N × 4 m.
3. = 280 J. | mechanics |
Power: 675 W. | null | phy_0758 | worked_example | en | A current of 15 A flows through 3 Ω. Compute the dissipated power. | [
"P = I²×R.",
"P = (15 A)² × 3 Ω.",
"= 675 W."
] | physics | Answer: Power: 675 W.
Steps:
1. P = I²×R.
2. P = (15 A)² × 3 Ω.
3. = 675 W. | electromagnetism |
Power: 180 W. | null | phy_0759 | worked_example | en | An engine does 1800 J of work in 10 s. Compute its power. | [
"P = W/t.",
"P = 1800 J / 10 s.",
"= 180 W."
] | physics | Answer: Power: 180 W.
Steps:
1. P = W/t.
2. P = 1800 J / 10 s.
3. = 180 W. | thermodynamics |
Magnification is 9×. | {
"A": "8×",
"B": "10×",
"C": "11×",
"D": "9×"
} | phy_0760 | multiple_choice | en | An image forms 90 cm from a lens, object at 10 cm. What is the magnification? | [
"M = 90 cm / 10 cm.",
"M = 9×.",
"Select option D."
] | physics | Answer: 9×
Steps:
1. M = 90 cm / 10 cm.
2. M = 9×.
3. Select option D.
Answer: (D) | optics |
3rd harmonic: 690 Hz. | null | phy_0761 | worked_example | en | A string's fundamental is 230 Hz. Compute its 3rd harmonic. | [
"f3 = 3×f1.",
"f3 = 3 × 230 Hz.",
"= 690 Hz."
] | physics | Answer: 3rd harmonic: 690 Hz.
Steps:
1. f3 = 3×f1.
2. f3 = 3 × 230 Hz.
3. = 690 Hz. | waves |
Mass number: 33. | null | phy_0762 | worked_example | en | A nucleus has 16 protons and 17 neutrons. Compute its mass number. | [
"A = Z+N.",
"A = 16 + 17.",
"= 33."
] | physics | Answer: Mass number: 33.
Steps:
1. A = Z+N.
2. A = 16 + 17.
3. = 33. | modern |
Momentum: 51 kg·m/s. | null | phy_0763 | worked_example | en | A mass of 17 kg moves at 3 m/s. Compute its momentum. | [
"p = m×v.",
"p = 17 kg × 3 m/s.",
"= 51 kg·m/s."
] | physics | Answer: Momentum: 51 kg·m/s.
Steps:
1. p = m×v.
2. p = 17 kg × 3 m/s.
3. = 51 kg·m/s. | mechanics |
Výkon UI ve wattech. | null | phy_0764 | concept | cs | Co je elektrický výkon? | [
"Výkon UI ve wattech.",
"Odpověď tedy platí: Výkon UI ve wattech."
] | physics | Answer: Výkon UI ve wattech.
Steps:
1. Výkon UI ve wattech.
2. Odpověď tedy platí: Výkon UI ve wattech. | electromagnetism |
Hot objects glow with spectra set by temperature alone, founding quantum theory. | null | phy_0765 | concept | en | What is blackbody radiation? | [
"Hot objects glow with spectra set by temperature alone, founding quantum theory.",
"So the answer stands: Hot objects glow with spectra set by temperature alone, founding quantum theory."
] | physics | Answer: Hot objects glow with spectra set by temperature alone, founding quantum theory.
Steps:
1. Hot objects glow with spectra set by temperature alone, founding quantum theory.
2. So the answer stands: Hot objects glow with spectra set by temperature alone, founding quantum theory. | thermodynamics |
Time is 8 s. | {
"A": "8 s",
"B": "9 s",
"C": "10 s",
"D": "7 s"
} | phy_0766 | multiple_choice | en | Light travels 24×10⁸ m. How many seconds does it take? (c = 3×10⁸ m/s) | [
"t = 24×10⁸ m / 3×10⁸ m/s.",
"t = 8 s.",
"Select option A."
] | physics | Answer: 8 s
Steps:
1. t = 24×10⁸ m / 3×10⁸ m/s.
2. t = 8 s.
3. Select option A.
Answer: (A) | optics |
Period is 0.12 s. | {
"A": "0.11 s",
"B": "0.1 s",
"C": "0.14 s",
"D": "0.12 s"
} | phy_0767 | multiple_choice | en | A wave has frequency 8 Hz. What is its period? | [
"T = 1 / 8 Hz.",
"T = 0.12 s.",
"Select option D."
] | physics | Answer: 0.12 s
Steps:
1. T = 1 / 8 Hz.
2. T = 0.12 s.
3. Select option D.
Answer: (D) | waves |
Survivors: 3000. | null | phy_0768 | worked_example | en | A sample of 12000 atoms undergoes 2 half-lives. Compute the survivors. | [
"Halve: 12000 → 6000.",
"Halve: 6000 → 3000.",
"= 3000."
] | physics | Answer: Survivors: 3000.
Steps:
1. Halve: 12000 → 6000.
2. Halve: 6000 → 3000.
3. = 3000. | modern |
It is the speed to leave a planet forever, 11.2 km/s from Earth. | null | phy_0769 | concept | en | What is escape velocity? | [
"It is the speed to leave a planet forever, 11.2 km/s from Earth.",
"So the answer stands: It is the speed to leave a planet forever, 11.2 km/s from Earth."
] | physics | Answer: It is the speed to leave a planet forever, 11.2 km/s from Earth.
Steps:
1. It is the speed to leave a planet forever, 11.2 km/s from Earth.
2. So the answer stands: It is the speed to leave a planet forever, 11.2 km/s from Earth. | mechanics |
Napětí: 48 V. | null | phy_0770 | worked_example | cs | Proud 4 A teče přes 12 Ω. Spočítej napětí. | [
"U = I×R.",
"U = 4 A × 12 Ω.",
"= 48 V."
] | physics | Answer: Napětí: 48 V.
Steps:
1. U = I×R.
2. U = 4 A × 12 Ω.
3. = 48 V. | electromagnetism |
Radiated power scales with T⁴, so small heating boosts glow hugely. | null | phy_0771 | concept | en | Why Stefan-Boltzmann? | [
"Radiated power scales with T⁴, so small heating boosts glow hugely.",
"So the answer stands: Radiated power scales with T⁴, so small heating boosts glow hugely."
] | physics | Answer: Radiated power scales with T⁴, so small heating boosts glow hugely.
Steps:
1. Radiated power scales with T⁴, so small heating boosts glow hugely.
2. So the answer stands: Radiated power scales with T⁴, so small heating boosts glow hugely. | thermodynamics |
Time: 14.3 s. | null | phy_0772 | worked_example | en | Light travels 43×10⁸ m. Compute the travel time. (c = 3×10⁸ m/s) | [
"t = d/c.",
"t = 43×10⁸ / 3×10⁸ s.",
"= 14.3 s."
] | physics | Answer: Time: 14.3 s.
Steps:
1. t = d/c.
2. t = 43×10⁸ / 3×10⁸ s.
3. = 14.3 s. | optics |
Abrupt pressure jumps from blasts outrun sound itself. | null | phy_0773 | concept | en | What is a shock wave? | [
"Abrupt pressure jumps from blasts outrun sound itself.",
"So the answer stands: Abrupt pressure jumps from blasts outrun sound itself."
] | physics | Answer: Abrupt pressure jumps from blasts outrun sound itself.
Steps:
1. Abrupt pressure jumps from blasts outrun sound itself.
2. So the answer stands: Abrupt pressure jumps from blasts outrun sound itself. | waves |
Lines: 153. | null | phy_0774 | worked_example | en | An atom is excited to level n = 18. Count the spectral lines it can emit. | [
"Pairs: 18×17/2.",
"= 306/2.",
"= 153."
] | physics | Answer: Lines: 153.
Steps:
1. Pairs: 18×17/2.
2. = 306/2.
3. = 153. | modern |
Net force: 32 N. | null | phy_0775 | worked_example | en | A mass of 16 kg accelerates at 2 m/s². Compute the net force. | [
"F = m×a.",
"F = 16 kg × 2 m/s².",
"= 32 N."
] | physics | Answer: Net force: 32 N.
Steps:
1. F = m×a.
2. F = 16 kg × 2 m/s².
3. = 32 N. | mechanics |
Power is 108 W. | {
"A": "96 W",
"B": "120 W",
"C": "132 W",
"D": "108 W"
} | phy_0776 | multiple_choice | en | A bulb runs at 12 V drawing 9 A. What is its power? | [
"P = 12 V × 9 A.",
"P = 108 W.",
"Select option D."
] | physics | Answer: 108 W
Steps:
1. P = 12 V × 9 A.
2. P = 108 W.
3. Select option D.
Answer: (D) | electromagnetism |
Temperature: 302 K. | null | phy_0777 | worked_example | en | Temperature is 29 °C. Convert it to kelvin. | [
"Add 273.",
"29 + 273.",
"= 302 K."
] | physics | Answer: Temperature: 302 K.
Steps:
1. Add 273.
2. 29 + 273.
3. = 302 K. | thermodynamics |
Locked phases let beams interfere and focus tightly over distance. | null | phy_0778 | concept | en | Why coherence matters? | [
"Locked phases let beams interfere and focus tightly over distance.",
"So the answer stands: Locked phases let beams interfere and focus tightly over distance."
] | physics | Answer: Locked phases let beams interfere and focus tightly over distance.
Steps:
1. Locked phases let beams interfere and focus tightly over distance.
2. So the answer stands: Locked phases let beams interfere and focus tightly over distance. | optics |
Speed: 2700 m/s. | null | phy_0779 | worked_example | en | A string wave has f = 900 Hz and λ = 3 m. Compute its speed. | [
"v = f×λ.",
"v = 900 Hz × 3 m.",
"= 2700 m/s."
] | physics | Answer: Speed: 2700 m/s.
Steps:
1. v = f×λ.
2. v = 900 Hz × 3 m.
3. = 2700 m/s. | waves |
Environment leaks quantumness away, turning blends classical. | null | phy_0780 | concept | en | What is decoherence? | [
"Environment leaks quantumness away, turning blends classical.",
"So the answer stands: Environment leaks quantumness away, turning blends classical."
] | physics | Answer: Environment leaks quantumness away, turning blends classical.
Steps:
1. Environment leaks quantumness away, turning blends classical.
2. So the answer stands: Environment leaks quantumness away, turning blends classical. | modern |
Work: 300 J. | null | phy_0781 | worked_example | en | A force of 75 N pushes 4 m. Compute the work done. | [
"W = F×d.",
"W = 75 N × 4 m.",
"= 300 J."
] | physics | Answer: Work: 300 J.
Steps:
1. W = F×d.
2. W = 75 N × 4 m.
3. = 300 J. | mechanics |
Voltage: 180 V. | null | phy_0782 | worked_example | en | A current of 15 A flows through 12 Ω. Compute the voltage. | [
"V = I×R.",
"V = 15 A × 12 Ω.",
"= 180 V."
] | physics | Answer: Voltage: 180 V.
Steps:
1. V = I×R.
2. V = 15 A × 12 Ω.
3. = 180 V. | electromagnetism |
Heat needed is 33488 J. | {
"A": "29302 J",
"B": "37674 J",
"C": "41860 J",
"D": "33488 J"
} | phy_0783 | multiple_choice | en | How much heat warms 1 kg of water by 8 K? (c = 4186 J/(kg·K)) | [
"Q = 1 kg × 4186 J/(kg·K) × 8 K.",
"Q = 33488 J.",
"Select option D."
] | physics | Answer: 33488 J
Steps:
1. Q = 1 kg × 4186 J/(kg·K) × 8 K.
2. Q = 33488 J.
3. Select option D.
Answer: (D) | thermodynamics |
Recorded interference rebuilds 3D light fields viewable around. | null | phy_0784 | concept | en | What is holography? | [
"Recorded interference rebuilds 3D light fields viewable around.",
"So the answer stands: Recorded interference rebuilds 3D light fields viewable around."
] | physics | Answer: Recorded interference rebuilds 3D light fields viewable around.
Steps:
1. Recorded interference rebuilds 3D light fields viewable around.
2. So the answer stands: Recorded interference rebuilds 3D light fields viewable around. | optics |
3rd harmonic is 510 Hz. | {
"A": "510 Hz",
"B": "480 Hz",
"C": "540 Hz",
"D": "570 Hz"
} | phy_0785 | multiple_choice | en | A string's fundamental is 170 Hz. What is its 3rd harmonic? | [
"f3 = 3 × 170 Hz.",
"f3 = 510 Hz.",
"Select option A."
] | physics | Answer: 510 Hz
Steps:
1. f3 = 3 × 170 Hz.
2. f3 = 510 Hz.
3. Select option A.
Answer: (A) | waves |
Conjugate pairs share spread limits set by Planck's constant. | null | phy_0786 | concept | en | Why uncertainty? | [
"Conjugate pairs share spread limits set by Planck's constant.",
"So the answer stands: Conjugate pairs share spread limits set by Planck's constant."
] | physics | Answer: Conjugate pairs share spread limits set by Planck's constant.
Steps:
1. Conjugate pairs share spread limits set by Planck's constant.
2. So the answer stands: Conjugate pairs share spread limits set by Planck's constant. | modern |
Kinetic energy is 121 J. | {
"A": "110 J",
"B": "121 J",
"C": "132 J",
"D": "143 J"
} | phy_0787 | multiple_choice | en | A 2 kg ball moves at 11 m/s. What is its kinetic energy? | [
"KE = ½×2 kg×(11 m/s)².",
"KE = 121 J.",
"Select option B."
] | physics | Answer: 121 J
Steps:
1. KE = ½×2 kg×(11 m/s)².
2. KE = 121 J.
3. Select option B.
Answer: (B) | mechanics |
Napětí je 15 V. | {
"A": "10 V",
"B": "15 V",
"C": "20 V",
"D": "25 V"
} | phy_0788 | multiple_choice | cs | Proud 3 A teče přes 5 Ω. Jaké je napětí? | [
"U = 3 A × 5 Ω.",
"U = 15 V.",
"Vyber možnost B."
] | physics | Answer: 15 V
Steps:
1. U = 3 A × 5 Ω.
2. U = 15 V.
3. Vyber možnost B.
Answer: (B) | electromagnetism |
Efficiency is 80%. | {
"A": "80%",
"B": "70%",
"C": "90%",
"D": "100%"
} | phy_0789 | multiple_choice | en | An engine turns 800 J of 1000 J heat into work. What is its efficiency? | [
"800 J / 1000 J.",
"= 80%.",
"Select option A."
] | physics | Answer: 80%
Steps:
1. 800 J / 1000 J.
2. = 80%.
3. Select option A.
Answer: (A) | thermodynamics |
Sklo ohýbá barvy různě. | null | phy_0790 | concept | cs | Co je rozklad světla? | [
"Sklo ohýbá barvy různě.",
"Odpověď tedy platí: Sklo ohýbá barvy různě."
] | physics | Answer: Sklo ohýbá barvy různě.
Steps:
1. Sklo ohýbá barvy různě.
2. Odpověď tedy platí: Sklo ohýbá barvy různě. | optics |
Distance: 5440 m. | null | phy_0791 | worked_example | en | Thunder is heard 16 s after lightning. How far away is the storm? (v = 340 m/s) | [
"d = v×t.",
"d = 340 m/s × 16 s.",
"= 5440 m."
] | physics | Answer: Distance: 5440 m.
Steps:
1. d = v×t.
2. d = 340 m/s × 16 s.
3. = 5440 m. | waves |
Intrinsic angular momentum with two outcomes, not real rotation. | null | phy_0792 | concept | en | What is spin? | [
"Intrinsic angular momentum with two outcomes, not real rotation.",
"So the answer stands: Intrinsic angular momentum with two outcomes, not real rotation."
] | physics | Answer: Intrinsic angular momentum with two outcomes, not real rotation.
Steps:
1. Intrinsic angular momentum with two outcomes, not real rotation.
2. So the answer stands: Intrinsic angular momentum with two outcomes, not real rotation. | modern |
Inverse-square gravity binds planets to ellipses, with speed varying by distance. | null | phy_0793 | concept | en | Why orbits ellipse? | [
"Inverse-square gravity binds planets to ellipses, with speed varying by distance.",
"So the answer stands: Inverse-square gravity binds planets to ellipses, with speed varying by distance."
] | physics | Answer: Inverse-square gravity binds planets to ellipses, with speed varying by distance.
Steps:
1. Inverse-square gravity binds planets to ellipses, with speed varying by distance.
2. So the answer stands: Inverse-square gravity binds planets to ellipses, with speed varying by distance. | mechanics |
Příkon je 48 W. | {
"A": "36 W",
"B": "60 W",
"C": "48 W",
"D": "72 W"
} | phy_0794 | multiple_choice | cs | Žárovka běží na 12 V a bere 4 A. Jaký je její příkon? | [
"P = 12 V × 4 A.",
"P = 48 W.",
"Vyber možnost C."
] | physics | Answer: 48 W
Steps:
1. P = 12 V × 4 A.
2. P = 48 W.
3. Vyber možnost C.
Answer: (C) | electromagnetism |
Mění tok tepla v práci. | null | phy_0795 | concept | cs | Proč tepelné stroje? | [
"Mění tok tepla v práci.",
"Odpověď tedy platí: Mění tok tepla v práci."
] | physics | Answer: Mění tok tepla v práci.
Steps:
1. Mění tok tepla v práci.
2. Odpověď tedy platí: Mění tok tepla v práci. | thermodynamics |
Total reflection pipes light for kilometres, carrying internet globally. | null | phy_0796 | concept | en | Why fibre optics? | [
"Total reflection pipes light for kilometres, carrying internet globally.",
"So the answer stands: Total reflection pipes light for kilometres, carrying internet globally."
] | physics | Answer: Total reflection pipes light for kilometres, carrying internet globally.
Steps:
1. Total reflection pipes light for kilometres, carrying internet globally.
2. So the answer stands: Total reflection pipes light for kilometres, carrying internet globally. | optics |
Speed is 900 m/s. | {
"A": "850 m/s",
"B": "950 m/s",
"C": "1000 m/s",
"D": "900 m/s"
} | phy_0797 | multiple_choice | en | A string wave has f = 450 Hz and λ = 2 m. What is its speed? | [
"v = 450 Hz × 2 m.",
"v = 900 m/s.",
"Select option D."
] | physics | Answer: 900 m/s
Steps:
1. v = 450 Hz × 2 m.
2. v = 900 m/s.
3. Select option D.
Answer: (D) | waves |
Vázané soustavy dovolují jen žebřík energií. | null | phy_0798 | concept | cs | Proč kvantování? | [
"Vázané soustavy dovolují jen žebřík energií.",
"Odpověď tedy platí: Vázané soustavy dovolují jen žebřík energií."
] | physics | Answer: Vázané soustavy dovolují jen žebřík energií.
Steps:
1. Vázané soustavy dovolují jen žebřík energií.
2. Odpověď tedy platí: Vázané soustavy dovolují jen žebřík energií. | modern |
Orbital period squared scales with distance cubed, timing every planet exactly. | null | phy_0799 | concept | en | What is Kepler's third law? | [
"Orbital period squared scales with distance cubed, timing every planet exactly.",
"So the answer stands: Orbital period squared scales with distance cubed, timing every planet exactly."
] | physics | Answer: Orbital period squared scales with distance cubed, timing every planet exactly.
Steps:
1. Orbital period squared scales with distance cubed, timing every planet exactly.
2. So the answer stands: Orbital period squared scales with distance cubed, timing every planet exactly. | mechanics |
Charge is 160 C. | {
"A": "160 C",
"B": "140 C",
"C": "180 C",
"D": "200 C"
} | phy_0800 | multiple_choice | en | A current of 4 A flows for 40 s. How much charge passes? | [
"Q = 4 A × 40 s.",
"Q = 160 C.",
"Select option A."
] | physics | Answer: 160 C
Steps:
1. Q = 4 A × 40 s.
2. Q = 160 C.
3. Select option A.
Answer: (A) | electromagnetism |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.