answer
string
choices
dict
id
string
kind
string
lang
string
question
string
steps
list
subject
string
text
string
topic
string
The voltage is 84 V.
{ "A": "72 V", "B": "84 V", "C": "96 V", "D": "108 V" }
eng_0051
multiple_choice
en
Current 7 A flows through 12 Ω. What is the voltage?
[ "I = 7 A, R = 12 Ω.", "V = IR = 84 V.", "Select option B (84 V)." ]
engineering
Answer: 84 V. Steps: 1. I = 7 A, R = 12 Ω. 2. V = IR = 84 V. 3. Select option B (84 V). Answer: (B)
circuits
Steady-state error is 10%.
{ "A": "12%", "B": "8%", "C": "10%", "D": "15%" }
eng_0052
multiple_choice
en
Type-0 loop has position constant Kp = 9. What is step steady-state error?
[ "Kp = 9 (dimensionless).", "ess = 100/10 = 10%.", "Select option C (10%)." ]
engineering
Answer: 10%. Steps: 1. Kp = 9 (dimensionless). 2. ess = 100/10 = 10%. 3. Select option C (10%). Answer: (C)
control
Dynamický tlak je 375 Pa.
null
eng_0053
worked_example
cs
Vzduch (ρ = 1,2 kg/m³) letí 25 m/s. Jaký je dynamický tlak?
[ "ρ = 1.2 kg/m³, v = 25 m/s.", "q = ½ρv² = 375 Pa.", "Result 375 Pa." ]
engineering
Answer: 375 Pa. Steps: 1. ρ = 1.2 kg/m³, v = 25 m/s. 2. q = ½ρv² = 375 Pa. 3. Result 375 Pa.
fluids
The mass is 39.25 kg.
null
eng_0054
worked_example
en
Steel part volume 0.005 m³ (ρ = 7850 kg/m³). What is its mass?
[ "V = 0.005 m³, ρ = 7850 kg/m³.", "m = ρV = 39.25 kg.", "Result 39.25 kg." ]
engineering
Answer: 39.25 kg. Steps: 1. V = 0.005 m³, ρ = 7850 kg/m³. 2. m = ρV = 39.25 kg. 3. Result 39.25 kg.
materials
The net moment is 1460 N·m clockwise.
null
eng_0055
worked_example
en
500 N at 4 m clockwise, 180 N at 3 m counter-clockwise. What is the net moment?
[ "M1 = 500×4 = 2000 N·m.", "M2 = 180×3 = 540 N·m.", "Net 1460 N·m." ]
engineering
Answer: 1460 N·m. Steps: 1. M1 = 500×4 = 2000 N·m. 2. M2 = 180×3 = 540 N·m. 3. Net 1460 N·m.
statics
Carnot efficiency is 50%.
{ "A": "55%", "B": "45%", "C": "50%", "D": "60%" }
eng_0056
multiple_choice
en
Carnot engine between 300 K and 600 K. What is its efficiency?
[ "Tc = 300 K, Th = 600 K.", "η = 1 − 300/600 = 50%.", "Select option C (50%)." ]
engineering
Answer: 50%. Steps: 1. Tc = 300 K, Th = 600 K. 2. η = 1 − 300/600 = 50%. 3. Select option C (50%). Answer: (C)
thermodynamics
The power is 1840 W.
{ "A": "1610 W", "B": "2070 W", "C": "1840 W", "D": "1955 W" }
eng_0057
multiple_choice
en
A 230 V appliance draws 8 A. What is its power?
[ "V = 230 V, I = 8 A.", "P = VI = 1840 W.", "Select option C (1840 W)." ]
engineering
Answer: 1840 W. Steps: 1. V = 230 V, I = 8 A. 2. P = VI = 1840 W. 3. Select option C (1840 W). Answer: (C)
circuits
The controller output is 40 V.
{ "A": "30 V", "B": "50 V", "C": "60 V", "D": "40 V" }
eng_0058
multiple_choice
en
P-controller with Kp = 2 V/V sees error 20 units. What is the output?
[ "Kp = 2 V/V, e = 20 units.", "u = Kp·e = 40 V.", "Select option D (40 V)." ]
engineering
Answer: 40 V. Steps: 1. Kp = 2 V/V, e = 20 units. 2. u = Kp·e = 40 V. 3. Select option D (40 V). Answer: (D)
control
Archimedes' principle says buoyancy equals the weight of displaced fluid.
null
eng_0059
concept
en
What is Archimedes' principle?
[ "Volume under.", "Times rho g.", "Floats if light." ]
engineering
Answer: Displaced weight. Steps: 1. Volume under. 2. Times rho g. 3. Floats if light.
fluids
Napětí je vnitřní síla na plochu, v pascalech či megapascalech.
null
eng_0060
concept
cs
Co je napětí v materiálu?
[ "N na m².", "MPa šikovné.", "Tah kladný." ]
engineering
Answer: Síla na plochu. Steps: 1. N na m². 2. MPa šikovné. 3. Tah kladný.
materials
Rameno je 14 m.
null
eng_0061
worked_example
cs
Moment 2100 N·m dělá síla 150 N. Jaké je rameno?
[ "M = 2100 N·m, F = 150 N.", "d = M/F = 14 m.", "Result 14 m." ]
engineering
Answer: 14 m. Steps: 1. M = 2100 N·m, F = 150 N. 2. d = M/F = 14 m. 3. Result 14 m.
statics
The heat required is 66.88 kJ.
{ "A": "76.88 kJ", "B": "56.88 kJ", "C": "86.88 kJ", "D": "66.88 kJ" }
eng_0062
multiple_choice
en
2 kg of water warms by 8 K (c = 4.18 kJ/(kg·K)). How much heat?
[ "m = 2 kg, ΔT = 8 K.", "Q = mcΔT = 66.88 kJ.", "Select option D (66.88 kJ)." ]
engineering
Answer: 66.88 kJ. Steps: 1. m = 2 kg, ΔT = 8 K. 2. Q = mcΔT = 66.88 kJ. 3. Select option D (66.88 kJ). Answer: (D)
thermodynamics
The stored charge is 3000 μC.
null
eng_0063
worked_example
en
Capacitor 300 μF charged to 10 V. What charge is stored?
[ "C = 300 μF, V = 10 V.", "Q = CV = 3000 μC.", "Result 3000 μC." ]
engineering
Answer: 3000 μC. Steps: 1. C = 300 μF, V = 10 V. 2. Q = CV = 3000 μC. 3. Result 3000 μC.
circuits
PID control sums proportional, integral, and derivative terms on the error.
null
eng_0064
concept
en
What is PID control?
[ "P reacts now.", "I removes offset.", "D damps." ]
engineering
Answer: P plus I plus D. Steps: 1. P reacts now. 2. I removes offset. 3. D damps.
control
The volume is 14 m³.
null
eng_0065
worked_example
en
Tank base area 2 m², depth 7 m. What is the water volume?
[ "A = 2 m², h = 7 m.", "V = Ah = 14 m³.", "Result 14 m³." ]
engineering
Answer: 14 m³. Steps: 1. A = 2 m², h = 7 m. 2. V = Ah = 14 m³. 3. Result 14 m³.
fluids
Elongation is 2.5 mm.
{ "A": "3.5 mm", "B": "1.5 mm", "C": "4.5 mm", "D": "2.5 mm" }
eng_0066
multiple_choice
en
Force 25 kN on 2 m steel bar (A = 100 mm², E = 200 GPa). What is elongation?
[ "F = 25 kN, L = 2 m.", "ΔL = FL/AE = 2.5 mm.", "Select option D (2.5 mm)." ]
engineering
Answer: 2.5 mm. Steps: 1. F = 25 kN, L = 2 m. 2. ΔL = FL/AE = 2.5 mm. 3. Select option D (2.5 mm). Answer: (D)
materials
The horizontal component is 240 N.
null
eng_0067
worked_example
en
Force 400 N pulls at a 3-4-5 angle. What is the horizontal component?
[ "F = 400 N, cos = 3/5.", "Fx = 0.6×400 = 240 N.", "Result 240 N." ]
engineering
Answer: 240 N. Steps: 1. F = 400 N, cos = 3/5. 2. Fx = 0.6×400 = 240 N. 3. Result 240 N.
statics
Internal energy rises 50 kJ.
{ "A": "50 kJ", "B": "55 kJ", "C": "45 kJ", "D": "60 kJ" }
eng_0068
multiple_choice
en
System gains 90 kJ of heat and does 40 kJ of work. What is internal energy change?
[ "Q = 90 kJ, W = 40 kJ.", "ΔU = Q−W = 50 kJ.", "Select option A (50 kJ)." ]
engineering
Answer: 50 kJ. Steps: 1. Q = 90 kJ, W = 40 kJ. 2. ΔU = Q−W = 50 kJ. 3. Select option A (50 kJ). Answer: (A)
thermodynamics
Total resistance is 1000 Ω.
{ "A": "900 Ω", "B": "1100 Ω", "C": "1050 Ω", "D": "1000 Ω" }
eng_0069
multiple_choice
en
Resistors 100 Ω and 900 Ω in series. What is total resistance?
[ "R1 = 100 Ω, R2 = 900 Ω.", "R = 1000 Ω.", "Select option D (1000 Ω)." ]
engineering
Answer: 1000 Ω. Steps: 1. R1 = 100 Ω, R2 = 900 Ω. 2. R = 1000 Ω. 3. Select option D (1000 Ω). Answer: (D)
circuits
P pushes with error, I clears steady offset, and D brakes on fast change.
null
eng_0070
concept
en
What do P, I, D terms do?
[ "P gain now.", "I sums past.", "D rates change." ]
engineering
Answer: Push clear brake. Steps: 1. P gain now. 2. I sums past. 3. D rates change.
control
Continuity says mass flow is constant, so area times velocity stays fixed.
null
eng_0071
concept
en
What is the continuity equation?
[ "Narrow pipe.", "Faster flow.", "Q constant." ]
engineering
Answer: Area times velocity. Steps: 1. Narrow pipe. 2. Faster flow. 3. Q constant.
fluids
Young's modulus is stiffness, stress over strain in gigapascals.
null
eng_0072
concept
en
What is Young's modulus?
[ "Steel 200 GPa.", "Alu 70 GPa.", "Steeper stiffer." ]
engineering
Answer: Stiffness slope. Steps: 1. Steel 200 GPa. 2. Alu 70 GPa. 3. Steeper stiffer.
materials
The moment is 800 N·m.
{ "A": "700 N·m", "B": "900 N·m", "C": "800 N·m", "D": "850 N·m" }
eng_0073
multiple_choice
en
Force 400 N acts at 2 m from a pivot. What is the moment?
[ "F = 400 N, d = 2 m.", "M = Fd = 800 N·m.", "Select option C (800 N·m)." ]
engineering
Answer: 800 N·m. Steps: 1. F = 400 N, d = 2 m. 2. M = Fd = 800 N·m. 3. Select option C (800 N·m). Answer: (C)
statics
The first law states energy is conserved: heat added equals internal rise plus work done.
null
eng_0074
concept
en
What is the first law of thermodynamics?
[ "Heat in J.", "Work in J.", "Internal stores." ]
engineering
Answer: Energy conserved. Steps: 1. Heat in J. 2. Work in J. 3. Internal stores.
thermodynamics
Ztrátový výkon je 120 W.
null
eng_0075
worked_example
cs
Proud 2 A odporem 30 Ω. Jaký je ztrátový výkon?
[ "I = 2 A, R = 30 Ω.", "P = I²R = 120 W.", "Result 120 W." ]
engineering
Answer: 120 W. Steps: 1. I = 2 A, R = 30 Ω. 2. P = I²R = 120 W. 3. Result 120 W.
circuits
PID regulace sčítá složky P, I a D z regulační odchylky.
null
eng_0076
concept
cs
Co je PID regulace?
[ "P tlačí hned.", "I maže trvalou.", "D tlumí." ]
engineering
Answer: P plus I plus D. Steps: 1. P tlačí hned. 2. I maže trvalou. 3. D tlumí.
control
The flow rate is 8 L/s.
{ "A": "6 L/s", "B": "10 L/s", "C": "8 L/s", "D": "12 L/s" }
eng_0077
multiple_choice
en
Pipe area 20 cm², velocity 4 m/s. What is flow in litres per second?
[ "A = 20 cm², v = 4 m/s.", "Q = Av = 8 L/s.", "Select option C (8 L/s)." ]
engineering
Answer: 8 L/s. Steps: 1. A = 20 cm², v = 4 m/s. 2. Q = Av = 8 L/s. 3. Select option C (8 L/s). Answer: (C)
fluids
The modulus is 62.1 GPa.
null
eng_0078
worked_example
en
Composite with fibre fraction 0.3 (Ef = 200 GPa, Em = 3 GPa). What is the modulus?
[ "Vf = 0.3, Ef = 200 GPa.", "E = VfEf+VmEm = 62.1 GPa.", "Result 62.1 GPa." ]
engineering
Answer: 62.1 GPa. Steps: 1. Vf = 0.3, Ef = 200 GPa. 2. E = VfEf+VmEm = 62.1 GPa. 3. Result 62.1 GPa.
materials
Max friction is 450 N.
{ "A": "500 N", "B": "400 N", "C": "550 N", "D": "450 N" }
eng_0079
multiple_choice
en
Normal force 900 N, friction coefficient 0.5. What is max friction?
[ "μ = 0.5 (dimensionless), N = 900 N.", "F = μN = 450 N.", "Select option D (450 N)." ]
engineering
Answer: 450 N. Steps: 1. μ = 0.5 (dimensionless), N = 900 N. 2. F = μN = 450 N. 3. Select option D (450 N). Answer: (D)
statics
Teplota je 87 °C.
null
eng_0080
worked_example
cs
Teplota je 360 K. Kolik je to stupňů Celsia?
[ "T = 360 K.", "C = 360 − 273 = 87 °C.", "Result 87 °C." ]
engineering
Answer: 87 °C. Steps: 1. T = 360 K. 2. C = 360 − 273 = 87 °C. 3. Result 87 °C.
thermodynamics
The current is 8 A.
null
eng_0081
worked_example
en
Voltage 48 V across 6 Ω. What is the current?
[ "V = 48 V, R = 6 Ω.", "I = V/R = 8 A.", "Result 8 A." ]
engineering
Answer: 8 A. Steps: 1. V = 48 V, R = 6 Ω. 2. I = V/R = 8 A. 3. Result 8 A.
circuits
Stability means bounded inputs give bounded outputs without runaway.
null
eng_0082
concept
en
What is stability?
[ "Poles left.", "No blowup.", "Margin kept." ]
engineering
Answer: Bounded stays bounded. Steps: 1. Poles left. 2. No blowup. 3. Margin kept.
control
The Reynolds number is 100000.
{ "A": "75000 (dimensionless)", "B": "125000 (dimensionless)", "C": "150000 (dimensionless)", "D": "100000 (dimensionless)" }
eng_0083
multiple_choice
en
Water at 2 m/s in 0.05 m pipe (μ = 0.001 Pa·s). What is the Reynolds number?
[ "ρ = 1000 kg/m³, v = 2 m/s, D = 0.05 m.", "Re = ρvD/μ = 100000 (dimensionless).", "Select option D (100000 (dimensionless))." ]
engineering
Answer: 100000 (dimensionless). Steps: 1. ρ = 1000 kg/m³, v = 2 m/s, D = 0.05 m. 2. Re = ρvD/μ = 100000 (dimensionless). 3. Select option D (100000 (dimensionless)). Answer: (D)
fluids
The shear stress is 32 MPa.
null
eng_0084
worked_example
en
Shear force 16 kN on 500 mm² section. What is the shear stress?
[ "F = 16 kN, A = 500 mm².", "τ = F/A = 32 MPa.", "Result 32 MPa." ]
engineering
Answer: 32 MPa. Steps: 1. F = 16 kN, A = 500 mm². 2. τ = F/A = 32 MPa. 3. Result 32 MPa.
materials
The vertical component is 360 N.
null
eng_0085
worked_example
en
Force 450 N pulls at a 3-4-5 angle. What is the vertical component?
[ "F = 450 N, sin = 4/5.", "Fy = 0.8×450 = 360 N.", "Result 360 N." ]
engineering
Answer: 360 N. Steps: 1. F = 450 N, sin = 4/5. 2. Fy = 0.8×450 = 360 N. 3. Result 360 N.
statics
The temperature is 318 K.
{ "A": "313 K", "B": "318 K", "C": "323 K", "D": "328 K" }
eng_0086
multiple_choice
en
Temperature is 45 °C. What is it in kelvin?
[ "T = 45 °C.", "K = 45 + 273 = 318 K.", "Select option B (318 K)." ]
engineering
Answer: 318 K. Steps: 1. T = 45 °C. 2. K = 45 + 273 = 318 K. 3. Select option B (318 K). Answer: (B)
thermodynamics
The equivalent is 50 Ω.
{ "A": "50 Ω", "B": "55 Ω", "C": "45 Ω", "D": "60 Ω" }
eng_0087
multiple_choice
en
Two 100 Ω resistors in parallel. What is the equivalent?
[ "R = 100 Ω each.", "Req = R/2 = 50 Ω.", "Select option A (50 Ω)." ]
engineering
Answer: 50 Ω. Steps: 1. R = 100 Ω each. 2. Req = R/2 = 50 Ω. 3. Select option A (50 Ω). Answer: (A)
circuits
The total gain is 14.
{ "A": "14 (dimensionless)", "B": "12 (dimensionless)", "C": "16 (dimensionless)", "D": "18 (dimensionless)" }
eng_0088
multiple_choice
en
Two series blocks have gains 2 and 7. What is the total gain?
[ "K1 = 2, K2 = 7 (dimensionless).", "K = 14 (dimensionless).", "Select option A (14 (dimensionless))." ]
engineering
Answer: 14 (dimensionless). Steps: 1. K1 = 2, K2 = 7 (dimensionless). 2. K = 14 (dimensionless). 3. Select option A (14 (dimensionless)). Answer: (A)
control
Hydraulic power is 1962 W.
null
eng_0089
worked_example
en
Pump lifts 0.02 m³/s of water 10 m. What hydraulic power is needed?
[ "Q = 0.02 m³/s, H = 10 m.", "P = ρgQH = 1962 W.", "Result 1962 W." ]
engineering
Answer: 1962 W. Steps: 1. Q = 0.02 m³/s, H = 10 m. 2. P = ρgQH = 1962 W. 3. Result 1962 W.
fluids
Thermal stress is 108 MPa.
null
eng_0090
worked_example
en
Steel bar (E = 200 GPa, α = 12e-6/K) cools 45 K constrained. What thermal stress arises?
[ "E = 200 GPa, ΔT = 45 K.", "σ = EαΔT = 108 MPa.", "Result 108 MPa." ]
engineering
Answer: 108 MPa. Steps: 1. E = 200 GPa, ΔT = 45 K. 2. σ = EαΔT = 108 MPa. 3. Result 108 MPa.
materials
The balancing reaction is 650 N upward.
{ "A": "650 N", "B": "700 N", "C": "600 N", "D": "750 N" }
eng_0091
multiple_choice
en
Downward forces 260 N and 390 N act on a beam. What upward reaction balances them?
[ "F1 = 260 N, F2 = 390 N.", "R = 260+390 = 650 N.", "Select option A (650 N)." ]
engineering
Answer: 650 N. Steps: 1. F1 = 260 N, F2 = 390 N. 2. R = 260+390 = 650 N. 3. Select option A (650 N). Answer: (A)
statics
The second law says entropy of an isolated system never decreases and heat flows hot to cold.
null
eng_0092
concept
en
What is the second law of thermodynamics?
[ "Hot to cold.", "No free lunch.", "Irreversible." ]
engineering
Answer: Entropy never falls. Steps: 1. Hot to cold. 2. No free lunch. 3. Irreversible.
thermodynamics
The resistance is 11 Ω.
null
eng_0093
worked_example
en
Voltage 33 V drives 3 A. What is the resistance?
[ "V = 33 V, I = 3 A.", "R = V/I = 11 Ω.", "Result 11 Ω." ]
engineering
Answer: 11 Ω. Steps: 1. V = 33 V, I = 3 A. 2. R = V/I = 11 Ω. 3. Result 11 Ω.
circuits
Stabilita znamená, že omezený vstup dá omezený výstup.
null
eng_0094
concept
cs
Co je stabilita systému?
[ "Póly vlevo.", "Bez úletu.", "Rezerva drží." ]
engineering
Answer: Omezené drží. Steps: 1. Póly vlevo. 2. Bez úletu. 3. Rezerva drží.
control
The buoyant force is 58860 N.
{ "A": "58860 N", "B": "49050 N", "C": "68670 N", "D": "78480 N" }
eng_0095
multiple_choice
en
A hull displaces 6 m³ of water. What is the buoyant force?
[ "V = 6 m³, ρ = 1000 kg/m³.", "F = ρgV = 58860 N.", "Select option A (58860 N)." ]
engineering
Answer: 58860 N. Steps: 1. V = 6 m³, ρ = 1000 kg/m³. 2. F = ρgV = 58860 N. 3. Select option A (58860 N). Answer: (A)
fluids
Deformace je poměrné prodloužení, bezrozměrné, často v mikrostrainu.
null
eng_0096
concept
cs
Co je deformace (strain)?
[ "Delta L lomeno L.", "Bez jednotek.", "Mikro škála." ]
engineering
Answer: Poměrné protažení. Steps: 1. Delta L lomeno L. 2. Bez jednotek. 3. Mikro škála.
materials
Síla je vektor s velikostí a směrem, měří se v newtonech.
null
eng_0097
concept
cs
Co je síla?
[ "Velikost v N.", "Směr platí.", "Sčítá vektory." ]
engineering
Answer: Vektor v newtonech. Steps: 1. Velikost v N. 2. Směr platí. 3. Sčítá vektory.
statics
The specific volume is 4 m³/kg.
null
eng_0098
worked_example
en
Gas fills 16 m³ with mass 4 kg. What is the specific volume?
[ "V = 16 m³, m = 4 kg.", "v = V/m = 4 m³/kg.", "Result 4 m³/kg." ]
engineering
Answer: 4 m³/kg. Steps: 1. V = 16 m³, m = 4 kg. 2. v = V/m = 4 m³/kg. 3. Result 4 m³/kg.
thermodynamics
Kirchhoff's current law says currents entering a node equal those leaving it.
null
eng_0099
concept
en
What is Kirchhoff's current law?
[ "Sum in amps.", "In equals out.", "Charge conserves." ]
engineering
Answer: Currents balance. Steps: 1. Sum in amps. 2. In equals out. 3. Charge conserves.
circuits
The error is 35 units.
null
eng_0100
worked_example
en
Setpoint 350 units, measurement 315 units. What is the error?
[ "r = 350 units, y = 315 units.", "e = r−y = 35 units.", "Result 35 units." ]
engineering
Answer: 35 units. Steps: 1. r = 350 units, y = 315 units. 2. e = r−y = 35 units. 3. Result 35 units.
control
Bernoulli's equation trades pressure, velocity, and height energy along a streamline.
null
eng_0101
concept
en
What is Bernoulli's equation?
[ "Fast means low p.", "High means low v.", "Steady ideal." ]
engineering
Answer: Energy tradeoff. Steps: 1. Fast means low p. 2. High means low v. 3. Steady ideal.
fluids
Příčná deformace je -780 mikrostrainu.
null
eng_0102
worked_example
cs
Tyč se natáhne o 2600 mikrostrainu, Poisson 0,3. Jaká je příčná deformace?
[ "εa = 2600 microstrain, ν = 0.3.", "εt = −νεa = -780 microstrain.", "Result -780 microstrain." ]
engineering
Answer: -780 microstrain. Steps: 1. εa = 2600 microstrain, ν = 0.3. 2. εt = −νεa = -780 microstrain. 3. Result -780 microstrain.
materials
The reaction at B is 1000 N.
null
eng_0103
worked_example
en
Beam 6 m, load 1500 N at 4 m from A. What is reaction at B?
[ "F = 1500 N, span 6 m.", "RB = 1500×4/6 = 1000 N.", "Result 1000 N." ]
engineering
Answer: 1000 N. Steps: 1. F = 1500 N, span 6 m. 2. RB = 1500×4/6 = 1000 N. 3. Result 1000 N.
statics
The work done is 220 kJ.
{ "A": "200 kJ", "B": "240 kJ", "C": "220 kJ", "D": "260 kJ" }
eng_0104
multiple_choice
en
Gas expands at 200 kPa by 1.1 m³. What work is done?
[ "p = 200 kPa, ΔV = 1.1 m³.", "W = pΔV = 220 kJ.", "Select option C (220 kJ)." ]
engineering
Answer: 220 kJ. Steps: 1. p = 200 kPa, ΔV = 1.1 m³. 2. W = pΔV = 220 kJ. 3. Select option C (220 kJ). Answer: (C)
thermodynamics
Ohmův zákon říká, že napětí je proud krát odpor, U rovná IR.
null
eng_0105
concept
cs
Co je Ohmův zákon?
[ "U ve voltech.", "I v ampérech.", "R v ohmech." ]
engineering
Answer: U rovná IR. Steps: 1. U ve voltech. 2. I v ampérech. 3. R v ohmech.
circuits
Ustálená hodnota je 30 jednotek.
{ "A": "25 units", "B": "30 units", "C": "35 units", "D": "40 units" }
eng_0106
multiple_choice
cs
Soustava K/(10s+1) s K = 30 dostane jednotkový skok. Jaká je ustálená hodnota?
[ "DC gain K = 30 (dimensionless).", "Step final = 30 units.", "Vyber možnost B (30 units)." ]
engineering
Answer: 30 units. Steps: 1. DC gain K = 30 (dimensionless). 2. Step final = 30 units. 3. Vyber možnost B (30 units). Answer: (B)
control
Přetlak je 68.67 kPa.
{ "A": "63.67 kPa", "B": "68.67 kPa", "C": "73.67 kPa", "D": "78.67 kPa" }
eng_0107
multiple_choice
cs
Hloubka vody je 7 m. Jaký je přetlak?
[ "ρ = 1000 kg/m³, h = 7 m.", "p = ρgh = 68.67 kPa.", "Vyber možnost B (68.67 kPa)." ]
engineering
Answer: 68.67 kPa. Steps: 1. ρ = 1000 kg/m³, h = 7 m. 2. p = ρgh = 68.67 kPa. 3. Vyber možnost B (68.67 kPa). Answer: (B)
fluids
Estimated strength is 980 MPa.
null
eng_0108
worked_example
en
Steel hardness 280 HB. Estimate tensile strength (UTS ≈ 3.5·HB).
[ "Hardness = 280 HB.", "UTS ≈ 3.5×280 = 980 MPa.", "Result 980 MPa." ]
engineering
Answer: 980 MPa. Steps: 1. Hardness = 280 HB. 2. UTS ≈ 3.5×280 = 980 MPa. 3. Result 980 MPa.
materials
Moment dvojice je 420 N·m.
{ "A": "450 N·m", "B": "420 N·m", "C": "390 N·m", "D": "480 N·m" }
eng_0109
multiple_choice
cs
Dvojice sil 140 N má rameno 3 m. Jaký je její moment?
[ "F = 140 N, d = 3 m.", "M = Fd = 420 N·m.", "Vyber možnost B (420 N·m)." ]
engineering
Answer: 420 N·m. Steps: 1. F = 140 N, d = 3 m. 2. M = Fd = 420 N·m. 3. Vyber možnost B (420 N·m). Answer: (B)
statics
The power is 500 W.
null
eng_0110
worked_example
en
Work 5000 J is done in 10 s. What is the power?
[ "W = 5000 J, t = 10 s.", "P = W/t = 500 W.", "Result 500 W." ]
engineering
Answer: 500 W. Steps: 1. W = 5000 J, t = 10 s. 2. P = W/t = 500 W. 3. Result 500 W.
thermodynamics
Energy used is 1100 Wh.
{ "A": "1000 Wh", "B": "1100 Wh", "C": "1200 Wh", "D": "1150 Wh" }
eng_0111
multiple_choice
en
A 550 W bulb burns 2 h. How much energy is used?
[ "P = 550 W, t = 2 h.", "E = Pt = 1100 Wh.", "Select option B (1100 Wh)." ]
engineering
Answer: 1100 Wh. Steps: 1. P = 550 W, t = 2 h. 2. E = Pt = 1100 Wh. 3. Select option B (1100 Wh). Answer: (B)
circuits
Settling time is about 32 s.
{ "A": "28 s", "B": "36 s", "C": "32 s", "D": "40 s" }
eng_0112
multiple_choice
en
First-order system has time constant 8 s. What is 2% settling time?
[ "τ = 8 s.", "ts ≈ 4τ = 32 s.", "Select option C (32 s)." ]
engineering
Answer: 32 s. Steps: 1. τ = 8 s. 2. ts ≈ 4τ = 32 s. 3. Select option C (32 s). Answer: (C)
control
Outlet velocity is 16 m/s.
{ "A": "14 m/s", "B": "18 m/s", "C": "16 m/s", "D": "20 m/s" }
eng_0113
multiple_choice
en
Pipe narrows from 0.02 m² to 0.01 m², inlet velocity 8 m/s. What is outlet velocity?
[ "A1v1 = 0.02×8 m³/s.", "v2 = 16 m/s.", "Select option C (16 m/s)." ]
engineering
Answer: 16 m/s. Steps: 1. A1v1 = 0.02×8 m³/s. 2. v2 = 16 m/s. 3. Select option C (16 m/s). Answer: (C)
fluids
The factor of safety is 2.
{ "A": "2 (dimensionless)", "B": "2.5 (dimensionless)", "C": "1.5 (dimensionless)", "D": "3 (dimensionless)" }
eng_0114
multiple_choice
en
Yield 300 MPa, working stress 150 MPa. What is the factor of safety?
[ "σy = 300 MPa, σw = 150 MPa.", "n = 2 (dimensionless).", "Select option A (2 (dimensionless))." ]
engineering
Answer: 2 (dimensionless). Steps: 1. σy = 300 MPa, σw = 150 MPa. 2. n = 2 (dimensionless). 3. Select option A (2 (dimensionless)). Answer: (A)
materials
Newton's first law says a body keeps its velocity unless a net force acts on it.
null
eng_0115
concept
en
What is Newton's first law?
[ "No net force.", "No acceleration.", "Inertia rules." ]
engineering
Answer: Keep velocity. Steps: 1. No net force. 2. No acceleration. 3. Inertia rules.
statics
Carnotova účinnost je 60 %.
{ "A": "65%", "B": "55%", "C": "70%", "D": "60%" }
eng_0116
multiple_choice
cs
Carnotův stroj mezi 300 K a 750 K. Jaká je jeho účinnost?
[ "Tc = 300 K, Th = 750 K.", "η = 1 − 300/750 = 60%.", "Vyber možnost D (60%)." ]
engineering
Answer: 60%. Steps: 1. Tc = 300 K, Th = 750 K. 2. η = 1 − 300/750 = 60%. 3. Vyber možnost D (60%). Answer: (D)
thermodynamics
Kirchhoff's voltage law says voltages around any loop sum to zero.
null
eng_0117
concept
en
What is Kirchhoff's voltage law?
[ "Add volts.", "Rises equal drops.", "Energy conserves." ]
engineering
Answer: Loop sums zero. Steps: 1. Add volts. 2. Rises equal drops. 3. Energy conserves.
circuits
Konečná hodnota je 24 jednotek.
null
eng_0118
worked_example
cs
Soustava se zesílením 8 dostane skok 3. Jaká je konečná hodnota?
[ "K = 8 (dimensionless), step 3 units.", "Final = 3×8 = 24 units.", "Result 24 units." ]
engineering
Answer: 24 units. Steps: 1. K = 8 (dimensionless), step 3 units. 2. Final = 3×8 = 24 units. 3. Result 24 units.
control
The flow rate is 18 L/s.
{ "A": "16 L/s", "B": "20 L/s", "C": "22 L/s", "D": "18 L/s" }
eng_0119
multiple_choice
en
Pipe area 20 cm², velocity 9 m/s. What is flow in litres per second?
[ "A = 20 cm², v = 9 m/s.", "Q = Av = 18 L/s.", "Select option D (18 L/s)." ]
engineering
Answer: 18 L/s. Steps: 1. A = 20 cm², v = 9 m/s. 2. Q = Av = 18 L/s. 3. Select option D (18 L/s). Answer: (D)
fluids
The stress is 70 MPa.
{ "A": "60 MPa", "B": "70 MPa", "C": "80 MPa", "D": "90 MPa" }
eng_0120
multiple_choice
en
Tensile force 7 kN on 100 mm² bar. What is the stress?
[ "F = 7 kN, A = 100 mm².", "σ = F/A = 70 MPa.", "Select option B (70 MPa)." ]
engineering
Answer: 70 MPa. Steps: 1. F = 7 kN, A = 100 mm². 2. σ = F/A = 70 MPa. 3. Select option B (70 MPa). Answer: (B)
materials
Each end reaction is 700 N.
null
eng_0121
worked_example
en
Uniform beam weighs 1400 N over 8 m. What is each end reaction?
[ "W = 1400 N, midspan 4 m.", "R = W/2 = 700 N.", "Result 700 N." ]
engineering
Answer: 700 N. Steps: 1. W = 1400 N, midspan 4 m. 2. R = W/2 = 700 N. 3. Result 700 N.
statics
Potřebné teplo je 108.68 kJ.
{ "A": "108.68 kJ", "B": "118.68 kJ", "C": "98.68 kJ", "D": "128.68 kJ" }
eng_0122
multiple_choice
cs
2 kg vody se ohřejí o 13 K (c = 4,18 kJ/(kg·K)). Kolik tepla?
[ "m = 2 kg, ΔT = 13 K.", "Q = mcΔT = 108.68 kJ.", "Vyber možnost A (108.68 kJ)." ]
engineering
Answer: 108.68 kJ. Steps: 1. m = 2 kg, ΔT = 13 K. 2. Q = mcΔT = 108.68 kJ. 3. Vyber možnost A (108.68 kJ). Answer: (A)
thermodynamics
Series resistors add directly, so total resistance is the sum in ohms.
null
eng_0123
concept
en
How do series resistors combine?
[ "Same current.", "Voltages split.", "R sums." ]
engineering
Answer: Add in series. Steps: 1. Same current. 2. Voltages split. 3. R sums.
circuits
Settling time is about 27 s.
null
eng_0124
worked_example
en
Time constant 9 s. What is 5% settling time?
[ "τ = 9 s.", "ts ≈ 3τ = 27 s.", "Result 27 s." ]
engineering
Answer: 27 s. Steps: 1. τ = 9 s. 2. ts ≈ 3τ = 27 s. 3. Result 27 s.
control
The Reynolds number is 225000.
{ "A": "225000 (dimensionless)", "B": "200000 (dimensionless)", "C": "250000 (dimensionless)", "D": "275000 (dimensionless)" }
eng_0125
multiple_choice
en
Water at 4.5 m/s in 0.05 m pipe (μ = 0.001 Pa·s). What is the Reynolds number?
[ "ρ = 1000 kg/m³, v = 4.5 m/s, D = 0.05 m.", "Re = ρvD/μ = 225000 (dimensionless).", "Select option A (225000 (dimensionless))." ]
engineering
Answer: 225000 (dimensionless). Steps: 1. ρ = 1000 kg/m³, v = 4.5 m/s, D = 0.05 m. 2. Re = ρvD/μ = 225000 (dimensionless). 3. Select option A (225000 (dimensionless)). Answer: (A)
fluids
Yield strength is the stress where permanent deformation begins.
null
eng_0126
concept
en
What is yield strength?
[ "Below elastic.", "Above stays bent.", "Design limit." ]
engineering
Answer: Plastic onset. Steps: 1. Below elastic. 2. Above stays bent. 3. Design limit.
materials
The resultant is 550 N.
{ "A": "500 N", "B": "600 N", "C": "550 N", "D": "650 N" }
eng_0127
multiple_choice
en
Forces 330 N east and 440 N north act on a bolt. What is the resultant?
[ "Fx = 330 N, Fy = 440 N.", "R = √(330²+440²) = 550 N.", "Select option C (550 N)." ]
engineering
Answer: 550 N. Steps: 1. Fx = 330 N, Fy = 440 N. 2. R = √(330²+440²) = 550 N. 3. Select option C (550 N). Answer: (C)
statics
Internal energy rises 75 kJ.
{ "A": "80 kJ", "B": "75 kJ", "C": "70 kJ", "D": "85 kJ" }
eng_0128
multiple_choice
en
System gains 140 kJ of heat and does 65 kJ of work. What is internal energy change?
[ "Q = 140 kJ, W = 65 kJ.", "ΔU = Q−W = 75 kJ.", "Select option B (75 kJ)." ]
engineering
Answer: 75 kJ. Steps: 1. Q = 140 kJ, W = 65 kJ. 2. ΔU = Q−W = 75 kJ. 3. Select option B (75 kJ). Answer: (B)
thermodynamics
The tap voltage is 13 V.
null
eng_0129
worked_example
en
Divider with two 1000 Ω resistors fed 26 V. What is the tap voltage?
[ "Vin = 26 V, halves.", "Vout = 13 V.", "Result 13 V." ]
engineering
Answer: 13 V. Steps: 1. Vin = 26 V, halves. 2. Vout = 13 V. 3. Result 13 V.
circuits
Steady-state error is the lasting gap between setpoint and output.
null
eng_0130
concept
en
What is steady-state error?
[ "Wait long.", "Read offset.", "Type sets it." ]
engineering
Answer: Lasting gap. Steps: 1. Wait long. 2. Read offset. 3. Type sets it.
control
Viscosity is a fluid's resistance to shearing flow.
null
eng_0131
concept
en
What is viscosity?
[ "Honey high.", "Water low.", "Pa·s unit." ]
engineering
Answer: Flow resistance. Steps: 1. Honey high. 2. Water low. 3. Pa·s unit.
fluids
The mass is 86.35 kg.
null
eng_0132
worked_example
en
Steel part volume 0.011 m³ (ρ = 7850 kg/m³). What is its mass?
[ "V = 0.011 m³, ρ = 7850 kg/m³.", "m = ρV = 86.35 kg.", "Result 86.35 kg." ]
engineering
Answer: 86.35 kg. Steps: 1. V = 0.011 m³, ρ = 7850 kg/m³. 2. m = ρV = 86.35 kg. 3. Result 86.35 kg.
materials
Moment je 1300 N·m.
{ "A": "1200 N·m", "B": "1400 N·m", "C": "1350 N·m", "D": "1300 N·m" }
eng_0133
multiple_choice
cs
Síla 650 N působí 2 m od čepu. Jaký je moment?
[ "F = 650 N, d = 2 m.", "M = Fd = 1300 N·m.", "Vyber možnost D (1300 N·m)." ]
engineering
Answer: 1300 N·m. Steps: 1. F = 650 N, d = 2 m. 2. M = Fd = 1300 N·m. 3. Vyber možnost D (1300 N·m). Answer: (D)
statics
The efficiency is 19%.
null
eng_0134
worked_example
en
Engine turns 190 J of 1000 J heat into work. What is the efficiency?
[ "W = 190 J, Q = 1000 J.", "η = W/Q = 19%.", "Result 19%." ]
engineering
Answer: 19%. Steps: 1. W = 190 J, Q = 1000 J. 2. η = W/Q = 19%. 3. Result 19%.
thermodynamics
The leaving current is 14 A.
null
eng_0135
worked_example
en
Currents 2 A and 12 A enter a node. What current leaves?
[ "I1 = 2 A, I2 = 12 A.", "I3 = 14 A.", "Result 14 A." ]
engineering
Answer: 14 A. Steps: 1. I1 = 2 A, I2 = 12 A. 2. I3 = 14 A. 3. Result 14 A.
circuits
Steady-state error is 20%.
{ "A": "22%", "B": "18%", "C": "25%", "D": "20%" }
eng_0136
multiple_choice
en
Type-0 loop has position constant Kp = 4. What is step steady-state error?
[ "Kp = 4 (dimensionless).", "ess = 100/5 = 20%.", "Select option D (20%)." ]
engineering
Answer: 20%. Steps: 1. Kp = 4 (dimensionless). 2. ess = 100/5 = 20%. 3. Select option D (20%). Answer: (D)
control
Tlak u dna je 107.91 kPa.
null
eng_0137
worked_example
cs
Sloupec klidné vody 11 m. Jaký je tlak u dna?
[ "ρ = 1000 kg/m³, h = 11 m.", "p = ρgh = 107.91 kPa.", "Result 107.91 kPa." ]
engineering
Answer: 107.91 kPa. Steps: 1. ρ = 1000 kg/m³, h = 11 m. 2. p = ρgh = 107.91 kPa. 3. Result 107.91 kPa.
fluids
The modulus is 81.8 GPa.
null
eng_0138
worked_example
en
Composite with fibre fraction 0.4 (Ef = 200 GPa, Em = 3 GPa). What is the modulus?
[ "Vf = 0.4, Ef = 200 GPa.", "E = VfEf+VmEm = 81.8 GPa.", "Result 81.8 GPa." ]
engineering
Answer: 81.8 GPa. Steps: 1. Vf = 0.4, Ef = 200 GPa. 2. E = VfEf+VmEm = 81.8 GPa. 3. Result 81.8 GPa.
materials
Newton's third law says every action has an equal and opposite reaction.
null
eng_0139
concept
en
What is Newton's third law?
[ "Push object.", "Object pushes back.", "Pair acts." ]
engineering
Answer: Equal opposite reaction. Steps: 1. Push object. 2. Object pushes back. 3. Pair acts.
statics
The new volume is 8 m³.
null
eng_0140
worked_example
en
Gas 3 m³ at 300 K warms to 800 K at constant pressure. What is the new volume?
[ "V1 = 3 m³, T1 = 300 K.", "V2 = 3×800/300 = 8 m³.", "Result 8 m³." ]
engineering
Answer: 8 m³. Steps: 1. V1 = 3 m³, T1 = 300 K. 2. V2 = 3×800/300 = 8 m³. 3. Result 8 m³.
thermodynamics
The voltage is 144 V.
{ "A": "132 V", "B": "156 V", "C": "144 V", "D": "168 V" }
eng_0141
multiple_choice
en
Current 12 A flows through 12 Ω. What is the voltage?
[ "I = 12 A, R = 12 Ω.", "V = IR = 144 V.", "Select option C (144 V)." ]
engineering
Answer: 144 V. Steps: 1. I = 12 A, R = 12 Ω. 2. V = IR = 144 V. 3. Select option C (144 V). Answer: (C)
circuits
The controller output is 90 V.
{ "A": "90 V", "B": "80 V", "C": "100 V", "D": "110 V" }
eng_0142
multiple_choice
en
P-controller with Kp = 2 V/V sees error 45 units. What is the output?
[ "Kp = 2 V/V, e = 45 units.", "u = Kp·e = 90 V.", "Select option A (90 V)." ]
engineering
Answer: 90 V. Steps: 1. Kp = 2 V/V, e = 45 units. 2. u = Kp·e = 90 V. 3. Select option A (90 V). Answer: (A)
control
The buoyant force is 107910 N.
{ "A": "98100 N", "B": "107910 N", "C": "117720 N", "D": "127530 N" }
eng_0143
multiple_choice
en
A hull displaces 11 m³ of water. What is the buoyant force?
[ "V = 11 m³, ρ = 1000 kg/m³.", "F = ρgV = 107910 N.", "Select option B (107910 N)." ]
engineering
Answer: 107910 N. Steps: 1. V = 11 m³, ρ = 1000 kg/m³. 2. F = ρgV = 107910 N. 3. Select option B (107910 N). Answer: (B)
fluids
The shear stress is 56 MPa.
null
eng_0144
worked_example
en
Shear force 28 kN on 500 mm² section. What is the shear stress?
[ "F = 28 kN, A = 500 mm².", "τ = F/A = 56 MPa.", "Result 56 MPa." ]
engineering
Answer: 56 MPa. Steps: 1. F = 28 kN, A = 500 mm². 2. τ = F/A = 56 MPa. 3. Result 56 MPa.
materials
Max friction is 700 N.
{ "A": "700 N", "B": "750 N", "C": "650 N", "D": "800 N" }
eng_0145
multiple_choice
en
Normal force 1400 N, friction coefficient 0.5. What is max friction?
[ "μ = 0.5 (dimensionless), N = 1400 N.", "F = μN = 700 N.", "Select option A (700 N)." ]
engineering
Answer: 700 N. Steps: 1. μ = 0.5 (dimensionless), N = 1400 N. 2. F = μN = 700 N. 3. Select option A (700 N). Answer: (A)
statics
The pressure is 1300 kPa.
null
eng_0146
worked_example
en
Gas 13 m³ at 100 kPa is squeezed to 1 m³ at constant temperature. What is the pressure?
[ "p1 = 100 kPa, V1 = 13 m³.", "p2 = 100×13 = 1300 kPa.", "Result 1300 kPa." ]
engineering
Answer: 1300 kPa. Steps: 1. p1 = 100 kPa, V1 = 13 m³. 2. p2 = 100×13 = 1300 kPa. 3. Result 1300 kPa.
thermodynamics
Příkon je 2990 W.
{ "A": "2760 W", "B": "3220 W", "C": "3105 W", "D": "2990 W" }
eng_0147
multiple_choice
cs
Spotřebič na 230 V odebírá 13 A. Jaký je jeho příkon?
[ "V = 230 V, I = 13 A.", "P = VI = 2990 W.", "Vyber možnost D (2990 W)." ]
engineering
Answer: 2990 W. Steps: 1. V = 230 V, I = 13 A. 2. P = VI = 2990 W. 3. Vyber možnost D (2990 W). Answer: (D)
circuits
Integrační výstup je 45 V.
null
eng_0148
worked_example
cs
Chyba 2 jednotky trvá 45 s při Ki = 0,5 1/s. Jaký je integrační výstup?
[ "e = 2 units, t = 45 s.", "u = 0.5×2×45 = 45 V.", "Result 45 V." ]
engineering
Answer: 45 V. Steps: 1. e = 2 units, t = 45 s. 2. u = 0.5×2×45 = 45 V. 3. Result 45 V.
control
Laminar flow is smooth layered motion while turbulent flow is chaotic mixing.
null
eng_0149
concept
en
How do laminar and turbulent flow differ?
[ "Low Re calm.", "High Re wild.", "Drag differs." ]
engineering
Answer: Smooth versus chaotic. Steps: 1. Low Re calm. 2. High Re wild. 3. Drag differs.
fluids
Thermal stress is 180 MPa.
null
eng_0150
worked_example
en
Steel bar (E = 200 GPa, α = 12e-6/K) cools 75 K constrained. What thermal stress arises?
[ "E = 200 GPa, ΔT = 75 K.", "σ = EαΔT = 180 MPa.", "Result 180 MPa." ]
engineering
Answer: 180 MPa. Steps: 1. E = 200 GPa, ΔT = 75 K. 2. σ = EαΔT = 180 MPa. 3. Result 180 MPa.
materials