Q2. A car accelerates from rest at 2 m/s² for 5 seconds. What is its final velocity?
Answer: 10 m/s
Use the equation v = u + at, where initial velocity u = 0.
📨 Send QueryQ3. A force of 10 N is applied to a 2 kg mass. What is its acceleration?
Answer: 5 m/s²
Newton’s second law: F = ma.
📨 Send QueryQ4. An object is dropped from a height of 45 m. How long does it take to hit the ground? (g = 10 m/s²)
Answer: 3 s
Use s = ut + (1/2)gt² with u = 0.
📨 Send QueryQ5. A 1000 kg car moving at 20 m/s has a kinetic energy of?
Answer: 200,000 J
Kinetic energy KE = (1/2)mv².
📨 Send QueryQ6. The weight of a 5 kg object on Earth (g = 9.8 m/s²) is approximately?
Answer: 49 N
Weight W = mg.
📨 Send QueryQ7. A wave has a frequency of 50 Hz and a wavelength of 2 m. What is its speed?
Answer: 100 m/s
Wave speed v = fλ.
📨 Send QueryQ8. A resistor of 10 Ω has a current of 2 A flowing through it. What is the voltage across it?
Answer: 20 V
Ohm’s law: V = IR.
📨 Send QueryQ9. The specific heat capacity of water is 4200 J/kg°C. How much energy is needed to heat 2 kg of water by 10°C?
Answer: 84,000 J
Use Q = mcΔT.
📨 Send QueryQ10. A lens has a focal length of 0.2 m. What is its power in diopters?
Answer: 5 D
Power P = 1/f (with f in meters).
📨 Send QueryQ11. The pressure exerted by a force of 100 N acting on an area of 5 m² is?
Answer: 20 Pa
Pressure P = F/A.
📨 Send QueryQ12. An object travels 30 m in 5 s at constant speed. What is its speed?
Answer: 6 m/s
Speed = distance ÷ time.
📨 Send QueryQ13. A 12 V battery is connected to a 4 Ω resistor. What is the current?
Answer: 3 A
Use Ohm’s law I = V/R.
📨 Send QueryQ15. A machine has an efficiency of 80% and gives an output work of 400 J. What is the input work?
Answer: 500 J
Efficiency = (Output/Input) × 100%.
📨 Send QueryQ16. The refractive index of water is 1.33. What is the speed of light in water? (c = 3 × 10⁸ m/s)
Answer: 2.25 × 10⁸ m/s
n = c/v.
📨 Send QueryQ17. A stone is thrown upward with an initial speed of 20 m/s. How high does it go? (g = 10 m/s²)
Answer: 20 m
At the top, v = 0. Use v² = u² – 2gh.
📨 Send QueryQ18. The heat required to melt 0.5 kg of ice (latent heat = 334,000 J/kg) is?
Answer: 167,000 J
Q = mL.
📨 Send QueryQ19. A spring constant is 200 N/m. How much force is needed to stretch it by 0.05 m?
Answer: 10 N
Hooke’s law: F = kx.
📨 Send QueryQ20. The time period of a pendulum of length 1 m (g = 9.8 m/s²) is approximately?
Answer: 2.0 s
T = 2π√(L/g).
📨 Send QueryQ21. A 60 W bulb is used for 5 hours. How much energy in kWh is consumed?
Answer: 0.3 kWh
Energy (kWh) = Power (kW) × Time (h).
📨 Send QueryQ22. The gravitational force between two 1 kg masses 1 m apart (G = 6.67 × 10⁻¹¹ Nm²/kg²) is?
Answer: 6.67 × 10⁻¹¹ N
Newton’s law of gravitation: F = G(m₁m₂/r²).
📨 Send QueryQ23. A sound wave has a speed of 340 m/s and a frequency of 170 Hz. What is its wavelength?
Answer: 2 m
λ = v/f.
📨 Send QueryQ24. A ball is thrown horizontally from a 20 m high cliff with a speed of 5 m/s. How far from the base does it land? (g = 10 m/s²)
Answer: 10 m
First find time to fall using vertical motion, then horizontal distance = speed × time.
📨 Send QueryQ25. The density of a 10 kg object with a volume of 0.002 m³ is?
Answer: 5000 kg/m³
Density ρ = m/V.
📨 Send QueryQ26. A parallel plate capacitor has a capacitance of 5 μF and a charge of 10 μC. What is the voltage?
Answer: 2 V
Q = CV.
📨 Send QueryQ27. A transformer steps down 220 V to 22 V. If the primary has 1000 turns, how many turns does the secondary have?
Answer: 100 turns
Vp/Vs = Np/Ns.
📨 Send QueryQ28. A 2 kg object is lifted vertically 3 m. The work done against gravity is (g = 10 m/s²)?
Answer: 60 J
Work = force × distance = mgh.
📨 Send QueryQ29. A train moving at 72 km/h comes to rest in 10 s. What is its deceleration in m/s²?
Answer: 2 m/s²
Convert km/h to m/s (÷ 3.6), then a = (v-u)/t.
📨 Send QueryQ30. The potential difference across a 5 Ω resistor when 100 J of heat is produced in 2 s is?
Answer: 10 V
Heat = (V²/R) t.
📨 Send QueryQ31. The critical angle for a material of refractive index 1.5 is approximately?
Answer: 41.8°
sin C = 1/n.
📨 Send QueryQ32. An electron (charge = 1.6 × 10⁻¹⁹ C) moves through a 10 V potential difference. Its gain in kinetic energy in eV is?
Answer: 10 eV
Energy in eV = voltage.
📨 Send QueryQ33. The focal length of a concave mirror is 15 cm. What is its radius of curvature?
Answer: 30 cm
R = 2f.
📨 Send QueryQ34. A hydraulic press has pistons of area 0.01 m² and 0.1 m². A 10 N force on the smaller piston gives what force on the larger?
Answer: 100 N
Pascal’s principle: F₁/A₁ = F₂/A₂.
📨 Send QueryQ35. The half-life of a radioactive substance is 2 days. What fraction remains after 6 days?
Answer: 1/8
Number of half-lives = total time / half-life.
📨 Send QueryQ36. A 2 m long wire has a resistance of 4 Ω. If stretched to 4 m (same volume), its new resistance is?
Answer: 16 Ω
Resistance is proportional to length² if volume constant.
📨 Send QueryQ37. A projectile is fired at 30° with speed 40 m/s. What is its maximum height? (g = 10 m/s²)
Answer: 20 m
H = (u² sin²θ)/(2g).
📨 Send QueryQ38. An ideal gas at 300 K has its temperature doubled at constant volume. What is its new pressure?
Answer: Twice the original
At constant volume, P ∝ T.
📨 Send QueryQ39. The energy stored in a 10 μF capacitor charged to 100 V is?
Answer: 0.05 J
E = (1/2)CV².
📨 Send QueryQ40. A 500 nm light wave has a frequency of? (c = 3 × 10⁸ m/s)
Answer: 6 × 10¹⁴ Hz
f = c/λ.
📨 Send QueryQ41. The centripetal acceleration of an object moving in a circle of radius 2 m at 4 m/s is?
Answer: 8 m/s²
a_c = v²/r.
📨 Send QueryQ42. A 2 A current flows for 5 minutes. How much charge passes?
Answer: 600 C
Charge Q = I × t (time in seconds).
📨 Send QueryQ43. The work done by a 30 N force pushing an object 4 m along the force direction is?
Answer: 120 J
Work = force × displacement × cosθ (θ=0° here).
📨 Send QueryQ44. The frequency of a simple pendulum of length 0.25 m (g = 9.8 m/s²) is approximately?
Answer: 1 Hz
f = (1/(2π))√(g/L).
📨 Send QueryQ45. The magnetic force on a 0.5 m wire carrying 4 A current perpendicular to a 0.1 T magnetic field is?
Answer: 0.2 N
F = BIL sinθ.
📨 Send QueryQ46. An object is placed 30 cm from a convex lens of focal length 20 cm. What is the image distance?
Answer: 60 cm
Use lens formula 1/f = 1/v – 1/u. Sign convention matters.
📨 Send QueryQ47. The escape velocity from Earth (g = 9.8 m/s², R = 6400 km) is approximately?
Answer: 11.2 km/s
v_esc = √(2gR).
📨 Send QueryQ48. The de Broglie wavelength of an electron (m = 9.1 × 10⁻³¹ kg) moving at 10⁶ m/s is approximately? (h = 6.63 × 10⁻³⁴ Js)
Answer: 7.28 × 10⁻¹⁰ m
λ = h/(mv).
📨 Send QueryQ49. The RMS speed of oxygen molecules (M = 0.032 kg/mol) at 300 K is approximately? (R = 8.31 J/mol·K)
Answer: 483 m/s
v_rms = √(3RT/M).
📨 Send QueryQ50. A 100 g object floats in water with 40% volume submerged. What is its density?
Answer: 400 kg/m³
Weight of object = weight of displaced water.
📨 Send QueryQ51. The power output of an engine that does 6000 J of work in 2 minutes is?
Answer: 50 W
Power = work ÷ time (in seconds).
📨 Send Query