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4
MCQ (Single Correct Answer)

There are two coils $A$ and $B$ as shown in figure. $A$ current starts flowing in $B$ as shown, when $A$ is moved towards $B$ and stops when $A$ stops moving. The current in $A$ is counter clockwise. $B$ is kept stationary when $A$ moves. We can infer that

A
there is a constant current in the clockwise direction in $A$
B
there is a varying current in $A$
C
there is no current in $A$
D
there is a constant current in the counter clockwise direction in $A$
5
MCQ (Single Correct Answer)

Same as problem 4 except the coil $A$ is made to rotate about a vertical axis (figure). No current flows in $B$ if $A$ is at rest. The current in coil $A$, when the current in $B($ at $t=0)$ is counter-clockwise and the coil $A$ is as shown at this instant, $t=0$, is

A
constant current clockwise
B
varying current clockwise
C
varying current counter clockwise
D
constant current counter clockwise
6
MCQ (Single Correct Answer)

The self inductance $L$ of a solenoid of length $l$ and area of cross-section $A$, with a fixed number of turns $N$ increases as

A
$l$ and $A$ increase
B
$l$ decreases and $A$ increases
C
$l$ increases and $A$ decreases
D
both $l$ and $A$ decrease
7
MCQ (Multiple Correct Answer)

A metal plate is getting heated. It can be because

A
a direct current is passing through the plate
B
it is placed in a time varying magnetic field
C
it is placed in a space varying magnetic field, but does not vary with time
D
a current (either direct or alternating) is passing through the plate
8
MCQ (Multiple Correct Answer)

An emf is produced in a coil, which is not connected to an external voltage source. This can be due to

A
the coil being in a time varying magnetic field
B
the coil moving in a time varying magnetic field
C
the coil moving in a constant magnetic field
D
the coil is stationary in external spatially varying magnetic field, which does not change with time
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