Science Group
Explore subjects and practice MCQs
7
Chapters
1,610
Total MCQs
Science Group
Answer: Ohm\'s law states that the voltage across a conductor is directly proportional to the current flowing through it, V = IR.
Answer: 1/R = 1/4 + 1/6 = (3+2)/12 = 5/12 → R = 12/5 = 2.4 Ω
Answer: I = V/R = 20/5 = 4 A
Answer: Energy has the same unit as work, which is Joule (J)
Answer: At the highest point of vertical motion, the instantaneous velocity becomes zero before the body starts falling down.
Answer: PE = mgh = 5 × 10 × 10 = 500 J
Answer: v = u + (F/m)t = 4 + (12/3)(1) = 4 + 4 = 8 m/s
Answer: T = 2π√(L/g) = 2π√(1/π²) = 2π/π = 2 s
Answer: In uniform circular motion, centripetal acceleration is always directed towards the center of the circle.
Answer: KE = p²/2m, so KE/p = p/2m = mv/2m = v/2
Answer: k = 2π, so λ = 2π/k = 2π/2π = 1 m
232
Answer: The apparent change in frequency of a wave due to relative motion between source and observer is the Doppler effect.
Answer: The speed of sound in air at standard temperature and pressure is approximately 340 m/s
Answer: A plane mirror always forms a virtual, erect image of the same size as the object.
Answer: v = c/n = (3 × 10⁸)/1.5 = 2 × 10⁸ m/s
Answer: Power is the rate of doing work, P = W/t
Answer: Gravity on the Moon is approximately 1/6 of Earth\'s gravity ≈ 1.6 m/s²
Answer: Gravitational force is conservative, so work done depends only on the initial and final positions (displacement).
Answer: The force on a current-carrying conductor in a magnetic field is the principle behind the working of an electric motor.
Answer: In series, R = R₁ + R₂ = 3 + 6 = 9 Ω