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At the time of short circuit, the current in the circuit increases heavily becomes the resistance of the conductor becomes almost zero.

It is false, the wire with green insulation is the earth wire, not the line wire.

Correct Answer is: (b) P₁ = P₂ < P₁

The LC circuit draws no power. When ωL = 1/ωL, the impedances of the RC and LR circuits are equal, and they draw the same power.

Correct Answer is: (b) decrease 

Current i = e/Z = eX/√(R² + X²) where X = 1/ωC.

Potential difference across C = V = iX = eX/√(R² + X²)

or V = e/√(1 + (R/X)²) = e/√(1 + (ωCR)²).

As ω increases, V will decrease

A) Both statements are true

Correct option is  D) zero

1. The magnetic lines are nearly circular in the vicinity of coil. 

2. Within the space enclosed by the wire the magnetic field lines are in the same direction. 

3. Near the centre of loop, the magnetic field lines are nearly parallel and the magnetic field may be assumed to be uniform in a small space near the centre. 

4. At the centre, the magnetic lines are along the axis of the loop and at right angles to the plane of the loop. 

5. The magnetic field lines become denser if the strength of current in the loop is increased and there are more number of turns in the loop.

Correct Answer is:(b) is directed out of the paper, (c) has magnitude μ₀i/2r (1 + 1/π)

The field at the centre of the loop due to the straight part is μ₀i/(2πr), directed into the paper, and the field due to the loop is μ₀i/(2r), directed out of the paper. 

1. Since the device is being used to step up 12V a.c. to 200V a.c., it is called a step up transformer. 

2. A transformer works on the principle of mutual induction. 

3. “When an alternating current is passed in the primary coil wound on the soft iron core, an induced emf- is produced in the secondary coil, wound on a soft iron

Right hand thumb rule or Maxwell’s cork screw rule.

It behaves as north pole.

It is approximately 50 Hz

It behaves as south pole

i) Along the axis of coil inwards. 

ii) Along the axis of coil outwards

Correct option is  B) Faraday

Correct option is  A) F, V, B

Correct option is  D) None

C) law of conservation of energy

• Law of conservation of energy says energy neither be created nor be destroyed, but can be converted from one form to another. 
• Faraday’s law says whenever there is a continuous change of magnetic flux linked with a closed coil, a current is generated in the coil. This induced EMF is equal to the rate of change of magnetic flux passing through it. 
• We have to do some work to move the magnet through a coil. This work produces energy. 
• This energy is converted into electrical energy in the coil. 
• In this way conservation of energy takes place in electromagnetic induction.

Yes, we can get. Here we have to ignore the friction everywhere.

1. The induced EMF generated in a closed loop is equal to the rate of change of magnetic flux passing through it. Induced EMF = Change in flux / time ε = ∆Φ / ∆t

2. Let Φ₀ be flux linked with single turn. If there are N turns of the coil, the flux linked with the coil is NΦ₀ . 

∴ ε = NAΦ₀ / ∆t

It is used in devices which convert mechanical energy into electrical energy.

In first three cases there is a change in magnetic flux. So electromagnetic induction occurs in first three cases

If the card is moved through a card reader, then a change in magnetic flux is produced in one direction, which induced potential or EMF. The current received by the pickup coil goes through signal amplification and translated into binary code, so that it can be read by computer.

C) Change of magnetic flux through the coil

A) the metal ring is levitated on the coil.

 Correct option is  D) mv/Bq

In OA and BC cases, E.M.F is induced.

Induced E.M.F = \(\frac {-(ϕ_2 - ϕ_1)}{t} = \frac {-[0-50]}{10}\)

= 50/10 = 5 Volt

D) Lenz’s law

Yes. But it depends on polarities of the horse shoe magnet.

Correct Answer is: (c) B = 0, for 0 ≤ x < r 

Correct Answer is: (c) If e is not 0, ϕ may or may not be 0.

Correct Answer is: (c) in unstable equilibrium