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A 5V battery is connected across the points X and Y. Assume D1 and D2 to be normal silicon diodes. Find the current supplied by the battery if the +ve terminal of the battery is connected to point X.

A 5V battery is connected across the points X and Y. Assume D1 and D2 to be normal silicon diodes. Find the current supplied by the battery if... View Article

A signal of 0.1 kW is transmitted in a cable. The attenuation of cable is -5 dB per km and cable length is 20 km. The power received at receiver is 10^-xW. The value of x is ______.

[Gain in dB = 10 log10(P0/Pi)] Answer: 8 Power of signal transmitted: Pi = 0.1 Kw = 100w Rate of attenuation = -5 dB/Km Total length of path... View Article

An electromagnetic wave of frequency 3 GHz enters a dielectric medium of relative electric permittivity 2.25 from vacuum. The wavelength of this wave in that medium will be _______ ×10^-2 cm.

Answer: 667 εr = 2.25 Assuming non-magnetic material ⇒ μr = 1 Hence refractive index of the medium n =... View Article

a series lcr circuit is designed to resonate at an angular frequency omega0 equal 105rad s the circuit draws 16W power from 120 v source at resonance the value of resistance in the circuit is omega

Answer: 900 P = V2/R 16 = 1202/R ⇒ R = 14400/16 ⇒ R = 900 Ω... View Article

The root mean square speed of molecules of a given mass of a gas at 27⁰C and 1 atmosphere pressure is 200 ms^-1. The root mean square speed of molecules of the gas at 127⁰C and 2 atmosphere pressure is x/√3 ms^-1. The value of x will be __________.

Answer: 400 m/s Vrms = √(3RT1/M0) 200 = √(3R×300/M0) ....(1) Also, x/√3 = √(3R×400/M0) …(2)... View Article

Two solids A and B of mass 1 kg and 2 kg respectively are moving with equal linear momentum. The ratio of their kinetic energies (K.E.)_A : (K.E.)_B will be A/1. So the value of A will be ________.

Answer: 2 Given that, M1/M2 = 1/2 we know that K = p2/2M K1/K2 = (p2/2M1 )×2M2/p2 K1/K2 = M2/M1 = 2/1 A/1 = 2/1 ⇒∴ A = 2... View Article

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

M	T	W	T	F	S	S
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