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A point charge of +12 μC is at a distance 6 cm vertically above the centre of a square of side 12 cm as shown in figure. The magnitude of the electric flux through the square will be _____ ×10³ Nm²/C.

A point charge of +12 μC is at a distance 6 cm vertically above the centre of a square of side 12 cm as shown in figure. The magnitude of the... View Article

A uniform thin bar of mass 6 kg and length 2.4 meter is bent to make an equilateral hexagon. The moment of inertia about an axis passing through the centre of mass and perpendicular to the plane of hexagon is ______×10^-1 kg m²

A uniform thin bar of mass 6 kg and length 2.4 meter is bent to make an equilateral hexagon. The moment of inertia about an axis passing through... View Article

Two cars are approaching each other at an equal speed of 7.2 km/hr. When they see each other, both blow horns having frequency of 676 Hz. The beat frequency heard by each driver will be ________ Hz. [Velocity of sound in air is 340 m/s.]

Two cars are approaching each other at an equal speed of 7.2 km/hr. When they see each other, both blow horns having frequency of 676 Hz. The... View Article

A cylindrical wire of radius 0.5 mm and conductivity 5×10⁷ S/m is subjected to an electric field of 10 mV/m. The expected value of current in the wire will be x³π mA. The value of x is ____.

Answer: 5 We know that J = σE ⇒ J = 5×107×10×10-3 ⇒ J = 50×104 A/m2 Current flowing; I = J × πR2... View Article

A uniform metallic wire is elongated by 0.04 m when subjected to a linear force F. The elongation, if its length and diameter is doubled and subjected to the same force will be ________ cm.

A uniform metallic wire is elongated by 0.04 m when subjected to a linear force F. The elongation, if its length and diameter is doubled and... View Article

A particle is projected with velocity v₀ along x-axis. A damping force is acting on the particle which is proportional to the square of the distance from the origin i.e. ma = -αx². The distance at which the particle stops:

a. (2v0/3α)1/3 b. (3v02/2α)1/2 c. (3v02/2α)1/3 d. (2v02/3α)1/2 Answer: Bonus a = vdv/dx Given:- vi = v0 Vf = 0 Xi = 0... View Article

Which of the following equations represents a travelling wave?

a. b. y = A sin(15x - 2t) c. y = Aex cos(ωt - θ) d. y = A sin x cos ωt Answer: (b) Y = F(x, t) For travelling wave y... View Article

A soft ferromagnetic material is placed in an external magnetic field. The magnetic domains:

a. decrease in size and changes orientation. b. may increase or decrease in size and change its orientation. c. increase in size but no change... View Article

Two electrons each are fixed at a distance ‘2d’. A third charge proton placed at the midpoint is displaced slightly by a distance x (x<<d) perpendicular to the line joining the two fixed charges. Proton will execute simple harmonic motion having angular frequency:

(m = mass of charged particle) a. (q2/2πε0md3)1/2 b. (πε0md3/2q2)1/2 c. (2πε0md3/q2)1/2 d.... View Article

The de Broglie wavelength of a proton and α-particle are equal. The ratio of their velocities is:

a. 4:2 b. 4:1 c. 1:4 d. 4:3 Answer: (b) Sol. From De-Broglie’s wavelength:- λ = h/mv Given λP = λα v... View Article

The figure shows a circuit that contains four identical resistors with resistance R = 2.0 Ω. Two identical inductors with inductance L = 2.0 mH and an ideal battery with emf E = 9.V. The current ‘i’ just after the switch ‘s’ is closed will be:

The figure shows a circuit that contains four identical resistors with resistance R = 2.0 Ω. Two identical inductors with inductance L =... View Article

In the given figure, a body of mass M is held between two massless springs, on a smooth inclined plane. The free ends of the springs are attached to firm supports. If each spring has spring constant k, the frequency of oscillation of given body is:

a. (1/2π) √(2K/Mg sin α) b. (1/2π) √(K/Mg sin α) c. (1/2π) √(2K/M) d. (1/2π) √(K/2M) Answer: (a) Equivalent K = K + K = 2K Now, T... View Article

The period of oscillation of a simple pendulum is T = 2π√(L/g). Measured value of ‘L’ is 1.0 m from meter-scale having a minimum division of 1 mm and time of one complete oscillation is 1.95 s measured from stopwatch of 0.01 s resolution. The percentage error in the determination of ‘g’ will be:

a. 1.33 % b. 1.30 % c. 1.13 % d. 1.03 % Answer: (c) T = 2π√(L/g) T2 = 4 2 [L/g] g = 4 2 [L/T2] Δg/g = ΔL/L + 2ΔT/T = [1mm/1m +... View Article

If one mole of an ideal gas at (P₁, V₁) is allowed to expand reversibly and isothermally (A to B) its pressure is reduced to one-half of the original pressure (see figure). This is followed by a constant volume cooling till its pressure is reduced to one-fourth of the initial value (B→C). Then it is restored to its initial state by a reversible adiabatic compression (C to A). The net work done by the gas is equal to:

If one mole of an ideal gas at (P1, V1) is allowed to expand reversibly and isothermally (A to B) its pressure is reduced to one-half of the... View Article

A body weighs 49 N on a spring balance at the north pole. What will be its weight recorded on the same weighing machine, if it is shifted to the equator?

[Use g = GM/R2 = 9.8 ms-2 and radius of earth, R = 6400 km.] a. 49 N b. 49.83 N c. 49.17 Nd d. 48.83 N Answer: (d) At North Pole, weight... View Article

Given below are two statements: Statement I: PN junction diodes can be used to function as transistor, simply by connecting two diodes, back to back, which acts as the base terminal. Statement II: In the study of transistor, the amplification factor β indicates ratio of the collector current to the base current.

In the light of the above statements, choose the correct answer from the options given below. a. Statement I is false but Statement II is true.... View Article

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