answer
string
choices
dict
id
string
kind
string
lang
string
question
string
steps
list
subject
string
text
string
topic
string
Bernoulliova rovnice směňuje tlak, rychlost a výšku podél proudnice.
null
eng_0251
concept
cs
Co je Bernoulliova rovnice?
[ "Rychle znamená tlak dolů.", "Vysoko pomalu.", "Stálé ideální." ]
engineering
Answer: Směna energií. Steps: 1. Rychle znamená tlak dolů. 2. Vysoko pomalu. 3. Stálé ideální.
fluids
The modulus is 101.5 GPa.
null
eng_0252
worked_example
en
Composite with fibre fraction 0.5 (Ef = 200 GPa, Em = 3 GPa). What is the modulus?
[ "Vf = 0.5, Ef = 200 GPa.", "E = VfEf+VmEm = 101.5 GPa.", "Result 101.5 GPa." ]
engineering
Answer: 101.5 GPa. Steps: 1. Vf = 0.5, Ef = 200 GPa. 2. E = VfEf+VmEm = 101.5 GPa. 3. Result 101.5 GPa.
materials
The moment arm is 38 m.
null
eng_0253
worked_example
en
Moment 5700 N·m comes from 150 N force. What is the moment arm?
[ "M = 5700 N·m, F = 150 N.", "d = M/F = 38 m.", "Result 38 m." ]
engineering
Answer: 38 m. Steps: 1. M = 5700 N·m, F = 150 N. 2. d = M/F = 38 m. 3. Result 38 m.
statics
The new volume is 11 m³.
null
eng_0254
worked_example
en
Gas 3 m³ at 300 K warms to 1100 K at constant pressure. What is the new volume?
[ "V1 = 3 m³, T1 = 300 K.", "V2 = 3×1100/300 = 11 m³.", "Result 11 m³." ]
engineering
Answer: 11 m³. Steps: 1. V1 = 3 m³, T1 = 300 K. 2. V2 = 3×1100/300 = 11 m³. 3. Result 11 m³.
thermodynamics
The power is 4140 W.
{ "A": "4140 W", "B": "3910 W", "C": "4370 W", "D": "4255 W" }
eng_0255
multiple_choice
en
A 230 V appliance draws 18 A. What is its power?
[ "V = 230 V, I = 18 A.", "P = VI = 4140 W.", "Select option A (4140 W)." ]
engineering
Answer: 4140 W. Steps: 1. V = 230 V, I = 18 A. 2. P = VI = 4140 W. 3. Select option A (4140 W). Answer: (A)
circuits
The integral output is 75 V.
null
eng_0256
worked_example
en
Error 2 units lasts 75 s with Ki = 0.5 1/s. What is the integral output?
[ "e = 2 units, t = 75 s.", "u = 0.5×2×75 = 75 V.", "Result 75 V." ]
engineering
Answer: 75 V. Steps: 1. e = 2 units, t = 75 s. 2. u = 0.5×2×75 = 75 V. 3. Result 75 V.
control
The mass flow is 16 kg/s.
null
eng_0257
worked_example
en
Water flows 16 L/s. What is the mass flow in kg/s?
[ "Q = 16 L/s, ρ = 1000 kg/m³.", "ṁ = 16 kg/s.", "Result 16 kg/s." ]
engineering
Answer: 16 kg/s. Steps: 1. Q = 16 L/s, ρ = 1000 kg/m³. 2. ṁ = 16 kg/s. 3. Result 16 kg/s.
fluids
Fatigue failure is cracking under repeated cyclic loads below static strength.
null
eng_0258
concept
en
What is fatigue failure?
[ "Load cycles.", "Crack grows.", "Sudden break." ]
engineering
Answer: Cyclic cracking. Steps: 1. Load cycles. 2. Crack grows. 3. Sudden break.
materials
The horizontal component is 600 N.
null
eng_0259
worked_example
en
Force 1000 N pulls at a 3-4-5 angle. What is the horizontal component?
[ "F = 1000 N, cos = 3/5.", "Fx = 0.6×1000 = 600 N.", "Result 600 N." ]
engineering
Answer: 600 N. Steps: 1. F = 1000 N, cos = 3/5. 2. Fx = 0.6×1000 = 600 N. 3. Result 600 N.
statics
An isothermal process holds temperature constant while heat and work exchange.
null
eng_0260
concept
en
What is an isothermal process?
[ "T fixed.", "Heat flows.", "Work matches." ]
engineering
Answer: Constant temperature. Steps: 1. T fixed. 2. Heat flows. 3. Work matches.
thermodynamics
An inductor stores magnetic energy and resists current change.
null
eng_0261
concept
en
What does an inductor do?
[ "Coil field.", "Current lags.", "DC passes." ]
engineering
Answer: Resists change. Steps: 1. Coil field. 2. Current lags. 3. DC passes.
circuits
The D output is 32 V.
null
eng_0262
worked_example
en
Error jumps 0 to 160 units in 2 s with Kd = 0.4 s. What is the D output?
[ "Slope = 160/2 units/s.", "u = 0.4×slope = 32 V.", "Result 32 V." ]
engineering
Answer: 32 V. Steps: 1. Slope = 160/2 units/s. 2. u = 0.4×slope = 32 V. 3. Result 32 V.
control
Gauge pressure is 166.77 kPa.
{ "A": "161.77 kPa", "B": "171.77 kPa", "C": "176.77 kPa", "D": "166.77 kPa" }
eng_0263
multiple_choice
en
Water depth is 17 m. What is gauge pressure?
[ "ρ = 1000 kg/m³, h = 17 m.", "p = ρgh = 166.77 kPa.", "Select option D (166.77 kPa)." ]
engineering
Answer: 166.77 kPa. Steps: 1. ρ = 1000 kg/m³, h = 17 m. 2. p = ρgh = 166.77 kPa. 3. Select option D (166.77 kPa). Answer: (D)
fluids
Bezpečnost je 2.5.
{ "A": "3.0 (dimensionless)", "B": "2.0 (dimensionless)", "C": "2.5 (dimensionless)", "D": "3.5 (dimensionless)" }
eng_0264
multiple_choice
cs
Mez kluzu 300 MPa, provozní napětí 120 MPa. Jaká je bezpečnost?
[ "σy = 300 MPa, σw = 120 MPa.", "n = 2.5 (dimensionless).", "Vyber možnost C (2.5 (dimensionless))." ]
engineering
Answer: 2.5 (dimensionless). Steps: 1. σy = 300 MPa, σw = 120 MPa. 2. n = 2.5 (dimensionless). 3. Vyber možnost C (2.5 (dimensionless)). Answer: (C)
materials
Těžiště je bod, kde je plocha či těleso v rovnováze.
null
eng_0265
concept
cs
Co je těžiště?
[ "Symetrie střed.", "Složené váží.", "Váha zde." ]
engineering
Answer: Střed rovnováhy. Steps: 1. Symetrie střed. 2. Složené váží. 3. Váha zde.
statics
The pressure is 1900 kPa.
null
eng_0266
worked_example
en
Gas 19 m³ at 100 kPa is squeezed to 1 m³ at constant temperature. What is the pressure?
[ "p1 = 100 kPa, V1 = 19 m³.", "p2 = 100×19 = 1900 kPa.", "Result 1900 kPa." ]
engineering
Answer: 1900 kPa. Steps: 1. p1 = 100 kPa, V1 = 19 m³. 2. p2 = 100×19 = 1900 kPa. 3. Result 1900 kPa.
thermodynamics
A short has near-zero resistance with large current, while an open has no path and zero current.
null
eng_0267
concept
en
How do short and open circuits differ?
[ "Short: big amps.", "Open: zero amps.", "Opposite faults." ]
engineering
Answer: Zero versus none. Steps: 1. Short: big amps. 2. Open: zero amps. 3. Opposite faults.
circuits
Výstup regulátoru je 140 V.
{ "A": "130 V", "B": "140 V", "C": "150 V", "D": "160 V" }
eng_0268
multiple_choice
cs
P-regulátor s Kp = 2 V/V vidí chybu 70 jednotek. Jaký je výstup?
[ "Kp = 2 V/V, e = 70 units.", "u = Kp·e = 140 V.", "Vyber možnost B (140 V)." ]
engineering
Answer: 140 V. Steps: 1. Kp = 2 V/V, e = 70 units. 2. u = Kp·e = 140 V. 3. Vyber možnost B (140 V). Answer: (B)
control
Dynamic pressure is 4335 Pa.
null
eng_0269
worked_example
en
Air (ρ = 1.2 kg/m³) moves 85 m/s. What is the dynamic pressure?
[ "ρ = 1.2 kg/m³, v = 85 m/s.", "q = ½ρv² = 4335 Pa.", "Result 4335 Pa." ]
engineering
Answer: 4335 Pa. Steps: 1. ρ = 1.2 kg/m³, v = 85 m/s. 2. q = ½ρv² = 4335 Pa. 3. Result 4335 Pa.
fluids
Creep is slow deformation under steady load at high temperature over time.
null
eng_0270
concept
en
What is creep?
[ "Heat softens.", "Load holds.", "Strain creeps." ]
engineering
Answer: Slow hot sag. Steps: 1. Heat softens. 2. Load holds. 3. Strain creeps.
materials
Static friction holds up to a limit before motion, while kinetic acts during sliding, usually lower.
null
eng_0271
concept
en
How do static and kinetic friction differ?
[ "Static holds.", "Kinetic slides.", "Static higher." ]
engineering
Answer: Before versus during. Steps: 1. Static holds. 2. Kinetic slides. 3. Static higher.
statics
Vykonaná práce je 420 kJ.
{ "A": "420 kJ", "B": "400 kJ", "C": "440 kJ", "D": "460 kJ" }
eng_0272
multiple_choice
cs
Plyn expanduje při 200 kPa o 2.1 m³. Jaká je práce?
[ "p = 200 kPa, ΔV = 2.1 m³.", "W = pΔV = 420 kJ.", "Vyber možnost A (420 kJ)." ]
engineering
Answer: 420 kJ. Steps: 1. p = 200 kPa, ΔV = 2.1 m³. 2. W = pΔV = 420 kJ. 3. Vyber možnost A (420 kJ). Answer: (A)
thermodynamics
The resistance is 23 Ω.
null
eng_0273
worked_example
en
Voltage 69 V drives 3 A. What is the resistance?
[ "V = 69 V, I = 3 A.", "R = V/I = 23 Ω.", "Result 23 Ω." ]
engineering
Answer: 23 Ω. Steps: 1. V = 69 V, I = 3 A. 2. R = V/I = 23 Ω. 3. Result 23 Ω.
circuits
The closed-loop gain is 0.95.
null
eng_0274
worked_example
en
Unity feedback loop, forward gain 19. What is the closed-loop gain?
[ "K = 19 (dimensionless).", "T = K/(1+K) = 0.95 (dimensionless).", "Result 0.95 (dimensionless)." ]
engineering
Answer: 0.95 (dimensionless). Steps: 1. K = 19 (dimensionless). 2. T = K/(1+K) = 0.95 (dimensionless). 3. Result 0.95 (dimensionless).
control
The volume is 38 m³.
null
eng_0275
worked_example
en
Tank base area 2 m², depth 19 m. What is the water volume?
[ "A = 2 m², h = 19 m.", "V = Ah = 38 m³.", "Result 38 m³." ]
engineering
Answer: 38 m³. Steps: 1. A = 2 m², h = 19 m. 2. V = Ah = 38 m³. 3. Result 38 m³.
fluids
The shear stress is 80 MPa.
null
eng_0276
worked_example
en
Shear force 40 kN on 500 mm² section. What is the shear stress?
[ "F = 40 kN, A = 500 mm².", "τ = F/A = 80 MPa.", "Result 80 MPa." ]
engineering
Answer: 80 MPa. Steps: 1. F = 40 kN, A = 500 mm². 2. τ = F/A = 80 MPa. 3. Result 80 MPa.
materials
Svislá složka je 840 N.
null
eng_0277
worked_example
cs
Síla 1050 N táhne pod úhlem 3-4-5. Jaká je svislá složka?
[ "F = 1050 N, sin = 4/5.", "Fy = 0.8×1050 = 840 N.", "Result 840 N." ]
engineering
Answer: 840 N. Steps: 1. F = 1050 N, sin = 4/5. 2. Fy = 0.8×1050 = 840 N. 3. Result 840 N.
statics
Teplota je 207 °C.
null
eng_0278
worked_example
cs
Teplota je 480 K. Kolik je to stupňů Celsia?
[ "T = 480 K.", "C = 480 − 273 = 207 °C.", "Result 207 °C." ]
engineering
Answer: 207 °C. Steps: 1. T = 480 K. 2. C = 480 − 273 = 207 °C. 3. Result 207 °C.
thermodynamics
A voltage divider splits input voltage across series resistors by ratio.
null
eng_0279
concept
en
What is a voltage divider?
[ "Two resistors.", "Tap middle.", "Vout fraction." ]
engineering
Answer: Split by ratio. Steps: 1. Two resistors. 2. Tap middle. 3. Vout fraction.
circuits
The total gain is 34.
{ "A": "32 (dimensionless)", "B": "36 (dimensionless)", "C": "34 (dimensionless)", "D": "38 (dimensionless)" }
eng_0280
multiple_choice
en
Two series blocks have gains 2 and 17. What is the total gain?
[ "K1 = 2, K2 = 17 (dimensionless).", "K = 34 (dimensionless).", "Select option C (34 (dimensionless))." ]
engineering
Answer: 34 (dimensionless). Steps: 1. K1 = 2, K2 = 17 (dimensionless). 2. K = 34 (dimensionless). 3. Select option C (34 (dimensionless)). Answer: (C)
control
A manometer measures pressure from a liquid column height difference.
null
eng_0281
concept
en
What does a manometer measure?
[ "Height in mm.", "Times rho g.", "Pa result." ]
engineering
Answer: Column pressure. Steps: 1. Height in mm. 2. Times rho g. 3. Pa result.
fluids
Teplotní napětí je 252 MPa.
null
eng_0282
worked_example
cs
Ocelová tyč (E = 200 GPa, α = 12e-6/K) chladne o 105 K vetknutá. Jaké vznikne napětí?
[ "E = 200 GPa, ΔT = 105 K.", "σ = EαΔT = 252 MPa.", "Result 252 MPa." ]
engineering
Answer: 252 MPa. Steps: 1. E = 200 GPa, ΔT = 105 K. 2. σ = EαΔT = 252 MPa. 3. Result 252 MPa.
materials
The reaction at B is 2200 N.
null
eng_0283
worked_example
en
Beam 6 m, load 3300 N at 4 m from A. What is reaction at B?
[ "F = 3300 N, span 6 m.", "RB = 3300×4/6 = 2200 N.", "Result 2200 N." ]
engineering
Answer: 2200 N. Steps: 1. F = 3300 N, span 6 m. 2. RB = 3300×4/6 = 2200 N. 3. Result 2200 N.
statics
The specific volume is 10 m³/kg.
null
eng_0284
worked_example
en
Gas fills 40 m³ with mass 4 kg. What is the specific volume?
[ "V = 40 m³, m = 4 kg.", "v = V/m = 10 m³/kg.", "Result 10 m³/kg." ]
engineering
Answer: 10 m³/kg. Steps: 1. V = 40 m³, m = 4 kg. 2. v = V/m = 10 m³/kg. 3. Result 10 m³/kg.
thermodynamics
The tap voltage is 25 V.
null
eng_0285
worked_example
en
Divider with two 1000 Ω resistors fed 50 V. What is the tap voltage?
[ "Vin = 50 V, halves.", "Vout = 25 V.", "Result 25 V." ]
engineering
Answer: 25 V. Steps: 1. Vin = 50 V, halves. 2. Vout = 25 V. 3. Result 25 V.
circuits
The error is 95 units.
null
eng_0286
worked_example
en
Setpoint 950 units, measurement 855 units. What is the error?
[ "r = 950 units, y = 855 units.", "e = r−y = 95 units.", "Result 95 units." ]
engineering
Answer: 95 units. Steps: 1. r = 950 units, y = 855 units. 2. e = r−y = 95 units. 3. Result 95 units.
control
Cavitation is vapor bubble collapse from low pressure, eroding pumps and propellers.
null
eng_0287
concept
en
What is cavitation?
[ "Pressure dips.", "Bubbles burst.", "Metal pits." ]
engineering
Answer: Bubble collapse. Steps: 1. Pressure dips. 2. Bubbles burst. 3. Metal pits.
fluids
Poisson's ratio is transverse shrink over axial stretch, about 0.3 for steel.
null
eng_0288
concept
en
What is Poisson's ratio?
[ "Pull bar.", "Sides pinch.", "Ratio 0.3." ]
engineering
Answer: Side over length. Steps: 1. Pull bar. 2. Sides pinch. 3. Ratio 0.3.
materials
Each end reaction is 1300 N.
null
eng_0289
worked_example
en
Uniform beam weighs 2600 N over 8 m. What is each end reaction?
[ "W = 2600 N, midspan 4 m.", "R = W/2 = 1300 N.", "Result 1300 N." ]
engineering
Answer: 1300 N. Steps: 1. W = 2600 N, midspan 4 m. 2. R = W/2 = 1300 N. 3. Result 1300 N.
statics
Carnot efficiency is 80%.
{ "A": "85%", "B": "80%", "C": "75%", "D": "90%" }
eng_0290
multiple_choice
en
Carnot engine between 300 K and 1500 K. What is its efficiency?
[ "Tc = 300 K, Th = 1500 K.", "η = 1 − 300/1500 = 80%.", "Select option B (80%)." ]
engineering
Answer: 80%. Steps: 1. Tc = 300 K, Th = 1500 K. 2. η = 1 − 300/1500 = 80%. 3. Select option B (80%). Answer: (B)
thermodynamics
Ground is the zero-volt reference node for all measurements.
null
eng_0291
concept
en
What is ground in a circuit?
[ "0 V defined.", "Currents return.", "Safety sink." ]
engineering
Answer: Zero reference. Steps: 1. 0 V defined. 2. Currents return. 3. Safety sink.
circuits
The steady value is 80 units.
{ "A": "75 units", "B": "85 units", "C": "90 units", "D": "80 units" }
eng_0292
multiple_choice
en
System K/(10s+1) with K = 80 gets a unit step. What is the steady value?
[ "DC gain K = 80 (dimensionless).", "Step final = 80 units.", "Select option D (80 units)." ]
engineering
Answer: 80 units. Steps: 1. DC gain K = 80 (dimensionless). 2. Step final = 80 units. 3. Select option D (80 units). Answer: (D)
control
Outlet velocity is 36 m/s.
{ "A": "36 m/s", "B": "34 m/s", "C": "38 m/s", "D": "40 m/s" }
eng_0293
multiple_choice
en
Pipe narrows from 0.02 m² to 0.01 m², inlet velocity 18 m/s. What is outlet velocity?
[ "A1v1 = 0.02×18 m³/s.", "v2 = 36 m/s.", "Select option A (36 m/s)." ]
engineering
Answer: 36 m/s. Steps: 1. A1v1 = 0.02×18 m³/s. 2. v2 = 36 m/s. 3. Select option A (36 m/s). Answer: (A)
fluids
The stress is 170 MPa.
{ "A": "160 MPa", "B": "180 MPa", "C": "190 MPa", "D": "170 MPa" }
eng_0294
multiple_choice
en
Tensile force 17 kN on 100 mm² bar. What is the stress?
[ "F = 17 kN, A = 100 mm².", "σ = F/A = 170 MPa.", "Select option D (170 MPa)." ]
engineering
Answer: 170 MPa. Steps: 1. F = 17 kN, A = 100 mm². 2. σ = F/A = 170 MPa. 3. Select option D (170 MPa). Answer: (D)
materials
The couple moment is 570 N·m.
{ "A": "600 N·m", "B": "540 N·m", "C": "570 N·m", "D": "630 N·m" }
eng_0295
multiple_choice
en
A couple has forces 190 N spaced 3 m apart. What is its moment?
[ "F = 190 N, d = 3 m.", "M = Fd = 570 N·m.", "Select option C (570 N·m)." ]
engineering
Answer: 570 N·m. Steps: 1. F = 190 N, d = 3 m. 2. M = Fd = 570 N·m. 3. Select option C (570 N·m). Answer: (C)
statics
The heat required is 192.28 kJ.
{ "A": "202.28 kJ", "B": "182.28 kJ", "C": "192.28 kJ", "D": "212.28 kJ" }
eng_0296
multiple_choice
en
2 kg of water warms by 23 K (c = 4.18 kJ/(kg·K)). How much heat?
[ "m = 2 kg, ΔT = 23 K.", "Q = mcΔT = 192.28 kJ.", "Select option C (192.28 kJ)." ]
engineering
Answer: 192.28 kJ. Steps: 1. m = 2 kg, ΔT = 23 K. 2. Q = mcΔT = 192.28 kJ. 3. Select option C (192.28 kJ). Answer: (C)
thermodynamics
Sériové odpory se sčítají, celkový odpor je součet v ohmech.
null
eng_0297
concept
cs
Co je sériové řazení odporů?
[ "Stejný proud.", "Napětí dělí.", "R součet." ]
engineering
Answer: Sčítání v sérii. Steps: 1. Stejný proud. 2. Napětí dělí. 3. R součet.
circuits
Doba ustálení je asi 72 s.
{ "A": "72 s", "B": "68 s", "C": "76 s", "D": "80 s" }
eng_0298
multiple_choice
cs
Soustava má časovou konstantu 18 s. Jaká je doba ustálení 2 %?
[ "τ = 18 s.", "ts ≈ 4τ = 72 s.", "Vyber možnost A (72 s)." ]
engineering
Answer: 72 s. Steps: 1. τ = 18 s. 2. ts ≈ 4τ = 72 s. 3. Vyber možnost A (72 s). Answer: (A)
control
Hydraulic power is 4316.4 W.
null
eng_0299
worked_example
en
Pump lifts 0.02 m³/s of water 22 m. What hydraulic power is needed?
[ "Q = 0.02 m³/s, H = 22 m.", "P = ρgQH = 4316.4 W.", "Result 4316.4 W." ]
engineering
Answer: 4316.4 W. Steps: 1. Q = 0.02 m³/s, H = 22 m. 2. P = ρgQH = 4316.4 W. 3. Result 4316.4 W.
fluids
Shear stress is parallel force per area sliding layers past each other.
null
eng_0300
concept
en
What is shear stress?
[ "Cut action.", "Tau symbol.", "Pa unit." ]
engineering
Answer: Sliding force. Steps: 1. Cut action. 2. Tau symbol. 3. Pa unit.
materials
The net moment is 380 N·m clockwise.
null
eng_0301
worked_example
en
500 N at 4 m clockwise, 540 N at 3 m counter-clockwise. What is the net moment?
[ "M1 = 500×4 = 2000 N·m.", "M2 = 540×3 = 1620 N·m.", "Net 380 N·m." ]
engineering
Answer: 380 N·m. Steps: 1. M1 = 500×4 = 2000 N·m. 2. M2 = 540×3 = 1620 N·m. 3. Net 380 N·m.
statics
Entropie měří rozptyl energie a vratně nikdy neklesá.
null
eng_0302
concept
cs
Co je entropie?
[ "Jouly na K.", "Stále roste.", "Limituje stroje." ]
engineering
Answer: Míra rozptylu. Steps: 1. Jouly na K. 2. Stále roste. 3. Limituje stroje.
thermodynamics
DC holds steady polarity while AC alternates direction periodically.
null
eng_0303
concept
en
How do AC and DC differ?
[ "Battery DC.", "Mains AC.", "Hz counts." ]
engineering
Answer: Steady versus alternating. Steps: 1. Battery DC. 2. Mains AC. 3. Hz counts.
circuits
Steady-state error is 4%.
{ "A": "6%", "B": "4%", "C": "2%", "D": "9%" }
eng_0304
multiple_choice
en
Type-0 loop has position constant Kp = 24. What is step steady-state error?
[ "Kp = 24 (dimensionless).", "ess = 100/25 = 4%.", "Select option B (4%)." ]
engineering
Answer: 4%. Steps: 1. Kp = 24 (dimensionless). 2. ess = 100/25 = 4%. 3. Select option B (4%). Answer: (B)
control
Base pressure is 225.63 kPa.
null
eng_0305
worked_example
en
Still water column 23 m high. What is pressure at the base?
[ "ρ = 1000 kg/m³, h = 23 m.", "p = ρgh = 225.63 kPa.", "Result 225.63 kPa." ]
engineering
Answer: 225.63 kPa. Steps: 1. ρ = 1000 kg/m³, h = 23 m. 2. p = ρgh = 225.63 kPa. 3. Result 225.63 kPa.
fluids
Transverse strain is -1500 microstrain.
null
eng_0306
worked_example
en
Bar stretches 5000 microstrain, Poisson ratio 0.3. What is transverse strain?
[ "εa = 5000 microstrain, ν = 0.3.", "εt = −νεa = -1500 microstrain.", "Result -1500 microstrain." ]
engineering
Answer: -1500 microstrain. Steps: 1. εa = 5000 microstrain, ν = 0.3. 2. εt = −νεa = -1500 microstrain. 3. Result -1500 microstrain.
materials
A centroid is the geometric center where area or volume balances.
null
eng_0307
concept
en
What is a centroid?
[ "Symmetric middle.", "Composite weighs.", "Used for weight." ]
engineering
Answer: Area balance point. Steps: 1. Symmetric middle. 2. Composite weighs. 3. Used for weight.
statics
Výkon je 1100 W.
null
eng_0308
worked_example
cs
Práce 11000 J za 10 s. Jaký je výkon?
[ "W = 11000 J, t = 10 s.", "P = W/t = 1100 W.", "Result 1100 W." ]
engineering
Answer: 1100 W. Steps: 1. W = 11000 J, t = 10 s. 2. P = W/t = 1100 W. 3. Result 1100 W.
thermodynamics
The leaving current is 26 A.
null
eng_0309
worked_example
en
Currents 2 A and 24 A enter a node. What current leaves?
[ "I1 = 2 A, I2 = 24 A.", "I3 = 26 A.", "Result 26 A." ]
engineering
Answer: 26 A. Steps: 1. I1 = 2 A, I2 = 24 A. 2. I3 = 26 A. 3. Result 26 A.
circuits
The final value is 60 units.
null
eng_0310
worked_example
en
Gain 20 system gets a step of amplitude 3. What is the final value?
[ "K = 20 (dimensionless), step 3 units.", "Final = 3×20 = 60 units.", "Result 60 units." ]
engineering
Answer: 60 units. Steps: 1. K = 20 (dimensionless), step 3 units. 2. Final = 3×20 = 60 units. 3. Result 60 units.
control
Reynoldsovo číslo je bezrozměrný poměr setrvačných a vazkých sil.
null
eng_0311
concept
cs
Co je Reynoldsovo číslo?
[ "Ró vé dé.", "Lomeno mí.", "Pod 2300 klid." ]
engineering
Answer: Setrvačnost lomeno vazkost. Steps: 1. Ró vé dé. 2. Lomeno mí. 3. Pod 2300 klid.
fluids
Deformace je 1700 mikrostrainu.
{ "A": "1700 microstrain", "B": "1600 microstrain", "C": "1800 microstrain", "D": "1900 microstrain" }
eng_0312
multiple_choice
cs
Tyč 1000 mm se protáhne o 1.7 mm. Jaká je deformace?
[ "ΔL = 1.7 mm, L = 1000 mm.", "ε = 1700 microstrain.", "Vyber možnost A (1700 microstrain)." ]
engineering
Answer: 1700 microstrain. Steps: 1. ΔL = 1.7 mm, L = 1000 mm. 2. ε = 1700 microstrain. 3. Vyber možnost A (1700 microstrain). Answer: (A)
materials
The resultant is 800 N.
{ "A": "750 N", "B": "850 N", "C": "900 N", "D": "800 N" }
eng_0313
multiple_choice
en
Forces 480 N east and 640 N north act on a bolt. What is the resultant?
[ "Fx = 480 N, Fy = 640 N.", "R = √(480²+640²) = 800 N.", "Select option D (800 N)." ]
engineering
Answer: 800 N. Steps: 1. Fx = 480 N, Fy = 640 N. 2. R = √(480²+640²) = 800 N. 3. Select option D (800 N). Answer: (D)
statics
An adiabatic process exchanges no heat, so work changes internal energy only.
null
eng_0314
concept
en
What is an adiabatic process?
[ "Insulated walls.", "Work only.", "T shifts." ]
engineering
Answer: No heat exchange. Steps: 1. Insulated walls. 2. Work only. 3. T shifts.
thermodynamics
Kondenzátor ukládá náboj a stejnosměrný proud nepropustí.
null
eng_0315
concept
cs
Co dělá kondenzátor?
[ "Desky drží Q.", "DC stojí.", "AC projde." ]
engineering
Answer: Ukládá náboj. Steps: 1. Desky drží Q. 2. DC stojí. 3. AC projde.
circuits
Doba ustálení je asi 63 s.
null
eng_0316
worked_example
cs
Časová konstanta 21 s. Jaká je doba ustálení 5 %?
[ "τ = 21 s.", "ts ≈ 3τ = 63 s.", "Result 63 s." ]
engineering
Answer: 63 s. Steps: 1. τ = 21 s. 2. ts ≈ 3τ = 63 s. 3. Result 63 s.
control
A boundary layer is the thin slowed fluid film along a solid wall.
null
eng_0317
concept
en
What is a boundary layer?
[ "Wall friction.", "Thin grows.", "Drag source." ]
engineering
Answer: Slowed wall film. Steps: 1. Wall friction. 2. Thin grows. 3. Drag source.
fluids
Toughness is energy absorbed before fracture, the area under the curve.
null
eng_0318
concept
en
What is toughness?
[ "Strong plus ductile.", "Area counts.", "Impact resists." ]
engineering
Answer: Energy to break. Steps: 1. Strong plus ductile. 2. Area counts. 3. Impact resists.
materials
The moment is 1800 N·m.
{ "A": "1800 N·m", "B": "1700 N·m", "C": "1900 N·m", "D": "1850 N·m" }
eng_0319
multiple_choice
en
Force 900 N acts at 2 m from a pivot. What is the moment?
[ "F = 900 N, d = 2 m.", "M = Fd = 1800 N·m.", "Select option A (1800 N·m)." ]
engineering
Answer: 1800 N·m. Steps: 1. F = 900 N, d = 2 m. 2. M = Fd = 1800 N·m. 3. Select option A (1800 N·m). Answer: (A)
statics
The efficiency is 31%.
null
eng_0320
worked_example
en
Engine turns 310 J of 1000 J heat into work. What is the efficiency?
[ "W = 310 J, Q = 1000 J.", "η = W/Q = 31%.", "Result 31%." ]
engineering
Answer: 31%. Steps: 1. W = 310 J, Q = 1000 J. 2. η = W/Q = 31%. 3. Result 31%.
thermodynamics
Total resistance is 2000 Ω.
{ "A": "1900 Ω", "B": "2000 Ω", "C": "2100 Ω", "D": "2050 Ω" }
eng_0321
multiple_choice
en
Resistors 100 Ω and 1900 Ω in series. What is total resistance?
[ "R1 = 100 Ω, R2 = 1900 Ω.", "R = 2000 Ω.", "Select option B (2000 Ω)." ]
engineering
Answer: 2000 Ω. Steps: 1. R1 = 100 Ω, R2 = 1900 Ω. 2. R = 2000 Ω. 3. Select option B (2000 Ω). Answer: (B)
circuits
The controller output is 190 V.
{ "A": "180 V", "B": "200 V", "C": "190 V", "D": "210 V" }
eng_0322
multiple_choice
en
P-controller with Kp = 2 V/V sees error 95 units. What is the output?
[ "Kp = 2 V/V, e = 95 units.", "u = Kp·e = 190 V.", "Select option C (190 V)." ]
engineering
Answer: 190 V. Steps: 1. Kp = 2 V/V, e = 95 units. 2. u = Kp·e = 190 V. 3. Select option C (190 V). Answer: (C)
control
Průtok je 38 L/s.
{ "A": "36 L/s", "B": "38 L/s", "C": "40 L/s", "D": "42 L/s" }
eng_0323
multiple_choice
cs
Průřez 20 cm², rychlost 19 m/s. Jaký je průtok v litrech za sekundu?
[ "A = 20 cm², v = 19 m/s.", "Q = Av = 38 L/s.", "Vyber možnost B (38 L/s)." ]
engineering
Answer: 38 L/s. Steps: 1. A = 20 cm², v = 19 m/s. 2. Q = Av = 38 L/s. 3. Vyber možnost B (38 L/s). Answer: (B)
fluids
Tvrdost je odpor povrchu proti vtlačení, stupnice Brinell či Rockwell.
null
eng_0324
concept
cs
Co je tvrdost?
[ "Vtlač tělísko.", "Malý důlek tvrdé.", "Vazba na otěr." ]
engineering
Answer: Odpor důlku. Steps: 1. Vtlač tělísko. 2. Malý důlek tvrdé. 3. Vazba na otěr.
materials
The moment arm is 50 m.
null
eng_0325
worked_example
en
Moment 7500 N·m comes from 150 N force. What is the moment arm?
[ "M = 7500 N·m, F = 150 N.", "d = M/F = 50 m.", "Result 50 m." ]
engineering
Answer: 50 m. Steps: 1. M = 7500 N·m, F = 150 N. 2. d = M/F = 50 m. 3. Result 50 m.
statics
Ideální plyn splňuje stavovou rovnici pV rovná nRT.
null
eng_0326
concept
cs
Co je ideální plyn?
[ "p v Pa.", "V v m³.", "T v K." ]
engineering
Answer: pV rovná nRT. Steps: 1. p v Pa. 2. V v m³. 3. T v K.
thermodynamics
The stored charge is 12000 μC.
null
eng_0327
worked_example
en
Capacitor 1200 μF charged to 10 V. What charge is stored?
[ "C = 1200 μF, V = 10 V.", "Q = CV = 12000 μC.", "Result 12000 μC." ]
engineering
Answer: 12000 μC. Steps: 1. C = 1200 μF, V = 10 V. 2. Q = CV = 12000 μC. 3. Result 12000 μC.
circuits
The integral output is 105 V.
null
eng_0328
worked_example
en
Error 2 units lasts 105 s with Ki = 0.5 1/s. What is the integral output?
[ "e = 2 units, t = 105 s.", "u = 0.5×2×105 = 105 V.", "Result 105 V." ]
engineering
Answer: 105 V. Steps: 1. e = 2 units, t = 105 s. 2. u = 0.5×2×105 = 105 V. 3. Result 105 V.
control
The Reynolds number is 475000.
{ "A": "450000 (dimensionless)", "B": "500000 (dimensionless)", "C": "475000 (dimensionless)", "D": "525000 (dimensionless)" }
eng_0329
multiple_choice
en
Water at 9.5 m/s in 0.05 m pipe (μ = 0.001 Pa·s). What is the Reynolds number?
[ "ρ = 1000 kg/m³, v = 9.5 m/s, D = 0.05 m.", "Re = ρvD/μ = 475000 (dimensionless).", "Select option C (475000 (dimensionless))." ]
engineering
Answer: 475000 (dimensionless). Steps: 1. ρ = 1000 kg/m³, v = 9.5 m/s, D = 0.05 m. 2. Re = ρvD/μ = 475000 (dimensionless). 3. Select option C (475000 (dimensionless)). Answer: (C)
fluids
Annealing heats and slowly cools metal to soften it and relieve stress.
null
eng_0330
concept
en
What is annealing?
[ "Heat up.", "Cool slow.", "Ductile again." ]
engineering
Answer: Soften by heat. Steps: 1. Heat up. 2. Cool slow. 3. Ductile again.
materials
A pin gives two reaction components while a roller gives one normal to the surface.
null
eng_0331
concept
en
How do pin and roller supports differ?
[ "Pin fixes x,y.", "Roller normal.", "Moments free." ]
engineering
Answer: Two versus one. Steps: 1. Pin fixes x,y. 2. Roller normal. 3. Moments free.
statics
The new volume is 14 m³.
null
eng_0332
worked_example
en
Gas 3 m³ at 300 K warms to 1400 K at constant pressure. What is the new volume?
[ "V1 = 3 m³, T1 = 300 K.", "V2 = 3×1400/300 = 14 m³.", "Result 14 m³." ]
engineering
Answer: 14 m³. Steps: 1. V1 = 3 m³, T1 = 300 K. 2. V2 = 3×1400/300 = 14 m³. 3. Result 14 m³.
thermodynamics
The power lost is 480 W.
null
eng_0333
worked_example
en
Current 2 A through 120 Ω. What power is lost?
[ "I = 2 A, R = 120 Ω.", "P = I²R = 480 W.", "Result 480 W." ]
engineering
Answer: 480 W. Steps: 1. I = 2 A, R = 120 Ω. 2. P = I²R = 480 W. 3. Result 480 W.
circuits
The D output is 44 V.
null
eng_0334
worked_example
en
Error jumps 0 to 220 units in 2 s with Kd = 0.4 s. What is the D output?
[ "Slope = 220/2 units/s.", "u = 0.4×slope = 44 V.", "Result 44 V." ]
engineering
Answer: 44 V. Steps: 1. Slope = 220/2 units/s. 2. u = 0.4×slope = 44 V. 3. Result 44 V.
control
The exit velocity is 20 m/s.
null
eng_0335
worked_example
en
Tank head 20 m (take g = 10 m/s²). What is the Torricelli velocity?
[ "h = 20 m, g = 10 m/s².", "v = √(2gh) = 20 m/s.", "Result 20 m/s." ]
engineering
Answer: 20 m/s. Steps: 1. h = 20 m, g = 10 m/s². 2. v = √(2gh) = 20 m/s. 3. Result 20 m/s.
fluids
Estimated strength is 1820 MPa.
null
eng_0336
worked_example
en
Steel hardness 520 HB. Estimate tensile strength (UTS ≈ 3.5·HB).
[ "Hardness = 520 HB.", "UTS ≈ 3.5×520 = 1820 MPa.", "Result 1820 MPa." ]
engineering
Answer: 1820 MPa. Steps: 1. Hardness = 520 HB. 2. UTS ≈ 3.5×520 = 1820 MPa. 3. Result 1820 MPa.
materials
The horizontal component is 780 N.
null
eng_0337
worked_example
en
Force 1300 N pulls at a 3-4-5 angle. What is the horizontal component?
[ "F = 1300 N, cos = 3/5.", "Fx = 0.6×1300 = 780 N.", "Result 780 N." ]
engineering
Answer: 780 N. Steps: 1. F = 1300 N, cos = 3/5. 2. Fx = 0.6×1300 = 780 N. 3. Result 780 N.
statics
Absolute zero is 0 K, the coldest limit where molecular motion is minimal.
null
eng_0338
concept
en
What is absolute zero?
[ "Minus 273 C.", "Unreachable limit.", "Entropy base." ]
engineering
Answer: Zero kelvin. Steps: 1. Minus 273 C. 2. Unreachable limit. 3. Entropy base.
thermodynamics
Ekvivalent je 100 Ω.
{ "A": "105 Ω", "B": "95 Ω", "C": "100 Ω", "D": "110 Ω" }
eng_0339
multiple_choice
cs
Dva odpory 200 Ω paralelně. Jaký je ekvivalent?
[ "R = 200 Ω each.", "Req = R/2 = 100 Ω.", "Vyber možnost C (100 Ω)." ]
engineering
Answer: 100 Ω. Steps: 1. R = 200 Ω each. 2. Req = R/2 = 100 Ω. 3. Vyber možnost C (100 Ω). Answer: (C)
circuits
The closed-loop gain is 0.96.
null
eng_0340
worked_example
en
Unity feedback loop, forward gain 24. What is the closed-loop gain?
[ "K = 24 (dimensionless).", "T = K/(1+K) = 0.96 (dimensionless).", "Result 0.96 (dimensionless)." ]
engineering
Answer: 0.96 (dimensionless). Steps: 1. K = 24 (dimensionless). 2. T = K/(1+K) = 0.96 (dimensionless). 3. Result 0.96 (dimensionless).
control
The mass flow is 22 kg/s.
null
eng_0341
worked_example
en
Water flows 22 L/s. What is the mass flow in kg/s?
[ "Q = 22 L/s, ρ = 1000 kg/m³.", "ṁ = 22 kg/s.", "Result 22 kg/s." ]
engineering
Answer: 22 kg/s. Steps: 1. Q = 22 L/s, ρ = 1000 kg/m³. 2. ṁ = 22 kg/s. 3. Result 22 kg/s.
fluids
Napětí je 190 MPa.
{ "A": "180 MPa", "B": "190 MPa", "C": "200 MPa", "D": "210 MPa" }
eng_0342
multiple_choice
cs
Ocel (E = 200 GPa) při deformaci 950 mikrostrainu. Jaké je napětí?
[ "E = 200 GPa, ε = 950 microstrain.", "σ = Eε = 190 MPa.", "Vyber možnost B (190 MPa)." ]
engineering
Answer: 190 MPa. Steps: 1. E = 200 GPa, ε = 950 microstrain. 2. σ = Eε = 190 MPa. 3. Vyber možnost B (190 MPa). Answer: (B)
materials
Svislá složka je 1080 N.
null
eng_0343
worked_example
cs
Síla 1350 N táhne pod úhlem 3-4-5. Jaká je svislá složka?
[ "F = 1350 N, sin = 4/5.", "Fy = 0.8×1350 = 1080 N.", "Result 1080 N." ]
engineering
Answer: 1080 N. Steps: 1. F = 1350 N, sin = 4/5. 2. Fy = 0.8×1350 = 1080 N. 3. Result 1080 N.
statics
Carnotův cyklus je ideální vratný oběh s největší účinností.
null
eng_0344
concept
cs
Co je Carnotův cyklus?
[ "Dvě izotermy.", "Dvě adiabaty.", "Určuje limit." ]
engineering
Answer: Ideální maximum. Steps: 1. Dvě izotermy. 2. Dvě adiabaty. 3. Určuje limit.
thermodynamics
The current is 26 A.
null
eng_0345
worked_example
en
Voltage 156 V across 6 Ω. What is the current?
[ "V = 156 V, R = 6 Ω.", "I = V/R = 26 A.", "Result 26 A." ]
engineering
Answer: 26 A. Steps: 1. V = 156 V, R = 6 Ω. 2. I = V/R = 26 A. 3. Result 26 A.
circuits
Časová konstanta je čas k 63 procentům skokové odezvy.
null
eng_0346
concept
cs
Co je časová konstanta?
[ "Tau v s.", "Značka tau.", "Měřítko rychlosti." ]
engineering
Answer: Čas 63 procent. Steps: 1. Tau v s. 2. Značka tau. 3. Měřítko rychlosti.
control
Vztlak je 206010 N.
{ "A": "196200 N", "B": "215820 N", "C": "225630 N", "D": "206010 N" }
eng_0347
multiple_choice
cs
Trup vytlačí 21 m³ vody. Jaký je vztlak?
[ "V = 21 m³, ρ = 1000 kg/m³.", "F = ρgV = 206010 N.", "Vyber možnost D (206010 N)." ]
engineering
Answer: 206010 N. Steps: 1. V = 21 m³, ρ = 1000 kg/m³. 2. F = ρgV = 206010 N. 3. Vyber možnost D (206010 N). Answer: (D)
fluids
The mass is 180.55 kg.
null
eng_0348
worked_example
en
Steel part volume 0.023 m³ (ρ = 7850 kg/m³). What is its mass?
[ "V = 0.023 m³, ρ = 7850 kg/m³.", "m = ρV = 180.55 kg.", "Result 180.55 kg." ]
engineering
Answer: 180.55 kg. Steps: 1. V = 0.023 m³, ρ = 7850 kg/m³. 2. m = ρV = 180.55 kg. 3. Result 180.55 kg.
materials
The method of joints solves truss member forces joint by joint with equilibrium.
null
eng_0349
concept
en
What is the method of joints?
[ "Isolate joint.", "Sum Fx,Fy zero.", "Find members." ]
engineering
Answer: Joint by joint. Steps: 1. Isolate joint. 2. Sum Fx,Fy zero. 3. Find members.
statics
Tlak je 2500 kPa.
null
eng_0350
worked_example
cs
Plyn 25 m³ při 100 kPa se stlačí na 1 m³ za stálé teploty. Jaký je tlak?
[ "p1 = 100 kPa, V1 = 25 m³.", "p2 = 100×25 = 2500 kPa.", "Result 2500 kPa." ]
engineering
Answer: 2500 kPa. Steps: 1. p1 = 100 kPa, V1 = 25 m³. 2. p2 = 100×25 = 2500 kPa. 3. Result 2500 kPa.
thermodynamics