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15 Nov 2021: The Hindu Analysis

UPSC Current Affairs Preparation: The Hindu Analysis Watch expert analysis of ‘The Hindu’ dated 15th Nov 2021. Important news and views to boost... View Article

Criminal Justice System in India

The aim of the Criminal Justice System is to punish the guilty and protect the innocent. Although the broad contours of the Criminal justice... View Article

If a coil of metal wire is kept stationary in a non-uniform magnetic field, then

1) An e.m.f. is induced in the coil 2) A current is induced in the coil 3) Neither e.m.f. nor current is induced 4) Both e.m.f. and current is... View Article

A rectangular coil of 20 turns and area of cross-section 25 sq cm has a resistance of 100 ohm. If a magnetic field which is perpendicular to the plane of the coil changes at the rate of 1000 tesla per second, the current in the coil is

1) 1.0 ampere 2) 50 ampere 3) 0.5 ampere 4) 5.0 ampere Answer: 3) 0.5 ampere Solution: i = ε/R = 0.5 A... View Article

The total charge induced in a conducting loop when it is moved in magnetic field depends on

1) The rate of change of magnetic flux 2) Initial magnetic flux only 3) The total change in magnetic flux 4) Final magnetic flux only... View Article

In a circuit with a coil of resistance 2 ohms, the magnetic flux changes from 2.0 Wb to 10.0 Wb in 0.2 seconds. The charge that flows in the coil during this time is

1) 5.0 coulomb 2) 4.0 coulomb 3) 1.0 coulomb 4) 0.8 coulomb Answer: 2) 4.0 coulomb Solution: ε0 = dΦ/dt = (10 -2)/0.2 = 40... View Article

A solenoid is 1.5 m long and its inner diameter is 4.0 cm. It has three layers of windings of 1000 turns each and carries a current of 2.0 amperes. The magnetic flux for a cross-section of the solenoid is nearly

1) 2.5 × 10–7 weber 2) 6.31 × 10–6 weber 3) 5.2 × 10–5 weber 4) 4.1 × 10–5 weber Answer: 2)... View Article

The direction of the induced current is such that it opposes the very cause that has produced it. This is the law of

1) Lenz 2) Faraday 3) Kirchhoff 4) Fleming Answer: 1) Lenz Solution: According to Lenz's law, the direction of the induced current is... View Article

A wire of length 50 cm moves with a velocity of 300 m/min, perpendicular to a magnetic field. If the e.m.f. induced in the wire is 2 V, the magnitude of the field in tesla is

1) 2 2) 5 3) 0.8 4) 2.5 Answer: 3) 0.8 Solution: When a wire of length l moves with a velocity v perpendicular to a magnetic field B,... View Article

The magnetic field in a coil of 100 turns and 40 square cm area is increased from 1 tesla to 6 tesla in 2 second. The magnetic field is perpendicular to the coil. The e.m.f. generated in it is

1) 104 V 2) 1.2 V 3) 1.0 V 4) 10–2 V Answer: 3) 1.0 V Solution: e = - N(ΔB/Δt).Acosθ = - 100 x [(6-1)/2] x 40... View Article

The north pole of a long horizontal bar magnet is being brought closer to a vertical conducting plane along the perpendicular direction. The direction of the induced current in the conducting plane will be

1) Horizontal 2) Vertical 3) Clockwise 4) Anticlockwise Answer: 4) Anticlockwise Solution: The direction of the induced current in the... View Article

The rms value of ac of 50 Hz is 10 amp. The time taken by the alternating current in reaching from zero to maximum value and the peak value of current will be,

1) 2 x 10-2 sec and 14.14 amp 2) 1 x 10-2 sec and 7.07 amp 3) 5 x 10-3 sec and 7.07 amp 4) 5 x 10-3 sec and 14.14 amp... View Article

An LC circuit contains a 20 mH inductor and a 50 μF capacitor with an initial charge of 10 mc. The resistance of the circuit is negligible. At the instant, the circuit is closed be t = 0. At what time is the energy stored completely magnetic

1) t = 0 2) t = 1.54 ms 3) t = 3.14 ms 4) t = 6.28 ms Answer: 2) t = 1.54 ms Solution: At t = T/4 energy stored is completely magnetic... View Article

In circular coil. when no. of turns is doubled & resistance becomes half of the initial then inductance becomes….

1) 4 times 2) 2 times 3) 8 times 4) No change Answer: 1) 4 times Solution: The formula for self-inductance L = μN2A/l So,... View Article

A solenoid of 1.5 m long with an inner diameter of 4 cm has three layers of winding of 1000 turns each & carries a current of 2 A. The magnetic flux through a cross-section of the solenoid is nearly…..

1) 2.5 x 10-7 wb 2) 6.31 x 10-6 wb 3) 2.1 x 10-6 wb 4) 4.1 x 10-5 wb Answer: 2) 6.31 x 10-6 wb Solution: Length of a... View Article

When a low flying aircraft passes overhead, we sometimes notice a slight shaking of the picture on our TV screen. This is due to

1) diffraction of the signal received from the antenna 2) interference of the direct signal received by the antenna with the weak signal... View Article

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