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A body is moved from rest along a straight line by a machine delivering constant power. Time taken by the body to travel a distance S is proportional to:

a. S1/3 b. S2/3 c. S1/2 d. S1/4 Solution: Answer: (b) Energy supplied in time t sec is, E = P × t Here P represents the power delivered... View Article

An electron having the de Broglie wavelength λ falls on an X-ray tube. The cut-off wavelength of emitted X-ray is

a. 2mcλ2 / hb. 2h / mcc. h / mcd. 2mcλ2 / 3hSolution:Answer: (a)De-broglie wavelength, λB = h / PP = h / (λB)Kinetic... View Article

Magnetic susceptibility of a material is 499 & μ₀ = 4π × 10⁻⁷ SI unit. Then find μ_r

a. 500b. 400c. 300d. 200Solution:Answer: (a)Given, = 499The relative permeability, μr = 1 + = 500... View Article

For a body in pure rolling, its rotational kinetic energy is 1/2 times of its translational kinetic energy. The body should be?

a. Solid cylinderb. Ringc. Solid sphered. Hollow sphereSolution:Answer: (a)Given,Rotational K.E = ½ Translational K.E½ Iω2 =... View Article

A sodium lamp in space was emitting waves of wavelength 2880 Å. When observed from a planet, its wavelength was recorded at 2886 Å. Find the speed of the planet?

a. 4.25 × 105 m/s b. 6.25 × 105 m/s c. 2.75 × 105 m/s d. 3.75 × 105 m/s Solution: Answer: (b) , ,... View Article

At 45° of the magnetic meridian angle of dip is 30° then find the angle of dip in a vertical plane at 45°?

a. tan−1(1/√6)b. tan−1(1/√2)c. tan−1 (1/√4)d. tan−1(1/√3)Solution:Answer: (a)Let the horizontal... View Article

Two satellites of mass M_A and M_B are revolving around a planet of mass M in radius R_A and R_B respectively. Then

a. TA > TBif RA > RB b. TA> TB if MA> MB c. TA= TB if MA> MB d. TA > TB if RA< RB Solution:Answer: (a)According to... View Article

A plane electromagnetic wave travels in free space. Electric field is [latex]left | vec{E} right |=E_{0}hat{i}[/latex] and magnetic field is represented by [latex]left | vec{B} right |=B_{0}hat{k}[/latex]. What is the unit vector along the direction of propagation of electromagnetic waves?

a.... View Article

In photoelectric effect stopping potential is 3V₀ for incident wavelength λ₀ and stopping potential for incident wavelength 2λ₀. Find threshold wavelength.

a. 3λ0 b. 2λ0 c. 4λ0 d. 8λ Solution:Answer: (c)KE = hv - WeV = hc / λ - WFor first casee(3Vo) = hc... View Article

Identify the correct graph between PV and T for an ideal gas.

Solution:Answer: (c)PV = nRT ⇒ PV=CTTherefore, PV v/s T graph is a straight line.... View Article

The velocities of a particle performing SHM at a distance of x1 and x2 from mean position are v1 and v2, find the time period of oscillation?

a. b. c. d. Solution: Answer: (c) , , , , , ,... View Article

Two identical drops of Hg coalesce to form a bigger drop. Find the ratio of the surface energy of a bigger drop to a smaller drop.

a. 2 3/2 b. 3 2/5 c. 2 2/3 d. 5 2/3 Solution: Answer: (c) , ,... View Article

Find the relation between γ(adiabatic constant) and degree of freedom (f).

a. f = 2 / γ - 1b. f = γ / γ - 1c. f = γ - 1 /2d. f = γ-1 / γSolution:Answer: (a)We know that,Cv = f R / 2Cp... View Article

Time (T), Velocity (C) and angular momentum (h) is chosen as fundamental quantities instead of mass, length and time. In terms of these, dimension of mass would be

a. [M] = [T-1 C-2 h]b. [M] = [T-1 C2 h]c. [M] = [T-1 C-2 h-1 ]d. [M] = [TC-2 h]Solution:Answer: (a)M ∝ Tx cy hz[ M1 L0 T0] = [Tx] [LT-1]y... View Article

Find the angle between vector P and vector Q

Question: a. 45° b. 90° c. 135° d. 150° Solution: Answer: (b) , , θ = 90°... View Article

A wheel rotating with an angular speed of 600 rpm is given a constant acceleration of 1800 rpm² for 10 sec. The number of revolutions revolved by the wheel is.

a. 125b. 100c. 75d. 50Solution:Answer: (a)ωo = 600 rpmα = 1800 rpm2t = 10 sec = 1/6 minθ = ωot + ½... View Article

For the given graph between decay rate and time find half-life (where R = decay rate)

a. 10 / 3 ln⁡2b. 20 / 3 ln⁡2c. 3 / 20 ln⁡2d. 3 / 10 ln⁡2Solution:Answer: (a)... View Article

A person walks up a stationary escalator in the time t₁. If he remains stationary on the escalator, then it can take him up in time t₂. Determine the time it would take to walk upon the moving escalator?

a. Solution: Answer: (a)Suppose length of escalator = LSpeed of man w.r.t escalator L / t1Speed of escalator = L / t2Speed of man w.r.t ground... View Article

A satellite is revolving around a planet in an orbit of radius R. Suddenly radius of orbit becomes 1.02 R, then what will be the percentage change in its time period of revolution?

a. 2% b. 3% c. 5% d. 7% Solution: Answer: (b) , ,... View Article

A RLC circuit is in its resonance condition. Its circuit components have value R = 5Ω, L = 2H, C = 0.5mF, V= 250V. Then find the power in the circuit.

a. 6 kWb. 10 kWc. 12 kWd. 12.5 kWSolution:Answer: (d)As the circuit is in resonance. Thus,XL = XC∴ Z = R so, irms = V / Z = V / R... View Article

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