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Sansad TV Perspective: Fighting Epidemics

In the series Sansad TV Perspective, we bring you an analysis of the discussion featured on the insightful programme ‘Perspective’ on Sansad TV,... View Article

30 Dec 2021: The Hindu Analysis

UPSC Current Affairs Preparation: The Hindu Analysis Watch expert analysis of ‘The Hindu’ dated 30 Dec 2021. Important news and views to boost... View Article

Rays from the Sun converge at a point 15 cm in front of a concave mirror. Where should an object be placed so that the size of its image is equal to the size of the object?

Solution: Since the sun is at an infinite distance from the surface of the earth, light rays from the sun rays after reflection from a concave... View Article

Energy of a photon having wave number 1.00 cm^{-1} is

a) b) c) d) Solution: b) Explanation:... View Article

A beam of electrons projected along +X axis, experiences a force due to a magnetic field along the +y-axis. What is the direction of the magnetic field?

Solution:... View Article

The moment P (in kg ms−1) of a particle is varying with time t (in second) as p=2+3t^2. The force acting on the particle at t=3s will be?

Solution: t=3s F=6*3=18N... View Article

Time constant of the given circuit is τ. If the battery is replaced by an AC source having voltage V=V0 cosωt, the power factor of the circuit will be?

Solution: Explanation:... View Article

A force given by the relation F= 8t acts on a body of mass 2 kg, initially at rest. Find the work done by this force on the body during the first 2 seconds of its motion.

a) 0 b) 1 c) -64 J d) 64 J Solution: d) 64 J Explanation: F=8t Work is said to be done when an object experiences displacement.... View Article

Two coils have self-inductance L1=4mH and L2=1mH respectively. The currents in the two coils are increased at the same rate. At a certain instant of time both coils are given the same power. If i1 and i2 are the currents in the two coils, at that instant of time respectively, then the value of (i1 /i2) is :

a) 0 b) 1 c) ½ d) ¼ Solution: d) ¼ Explanation:... View Article

If we change the value of R, then

a) Voltage does not change on C b) Voltage does not change on L c) Voltage change on LC combination d) Voltage does not change on LC... View Article

In a wave E0 =100Vm−1. Find the poynting vector magnitude.

Solution:... View Article

A square coil ACDE with it’s plane vertical is released from rest in a horizontal uniform magnetic field B of length 2L ( as shown in figure). The acceleration of the coil is

< p>a) g all the time b) less than g for all time till the loop crosses the magnetic field completely c) less than g when it enters the field... View Article

When a loop moves towards a stationary magnet with speed v, the induced emf in the loop is E. If the magnet also moves away from the loop with the same speed, then the emf induced in the loop is

a) E b) 2E c) E/2 d) Zero Solution: d) zero Explanation: If loop and a stationary magnet move with the same velocity in the same direction,... View Article

A small signal voltage V(t)= V0sinωt V(t)=V0sinωt is applied across an ideal capacitor C:

a) Current I (t) is in phase with voltage V(t) b) Over a full cycle the capacitor C does not consume any energy from the voltage source c)... View Article

Two weights w1 and w2 are suspended on the ends of a string on a frictionless pulley. When pulled up with an acceleration g, the tension in the string is?

Solution: for second weight... View Article

Which wavelength of sun is used finally as electric energy?

a) Visible light b) Radio waves c) Microwaves d) Infrared waves Solution: d) Infrared waves Explanation: Infrared waves also known as heat... View Article

An electric bulb is designed to operate at 12 volts DC. If this bulb is connected to an AC source and gives normal brightness , what would be the peak voltage of the source?

Solution: Potential =12v Hence, the RMS value of the AC voltage must be equal to 12v. The peak value of the voltage is: = 16.85 V Hence, the... View Article

An inductor may store energy in?

a) its magnetic field b) its electric field c) its coil d) both electric and magnetic fields Solution: a) its magnetic field. Explanation:... View Article

A 150 m long metal wire connects points A and B. The electric potential at point B is 50V less than that at point A. If the conductivity of the metal is 60 × 10^6 mho/m then magnitude of the current density in the wire is equal to?

Solution:... View Article

Taking into account the significant figures, what is the value of 9.99m−0.0099m?

a) 9.98m b) 9.980m c) 9.980m d) 9.9801m <strong>Solution:</strong> a) 9.98m Explanation: 9.99m−0.0099m=9.9801m = 9.98m... View Article

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