Physics-
General
Easy
Question
A conducting ring is placed around the core of an electromagnet as shown in fig. When key K is pressed, the ring

- Remain stationary
- Is attracted towards the electromagnet
- Jumps out of the core
- None of the above
The correct answer is: Jumps out of the core
When key k is pressed, current through the electromagnet start increasing i.e. flux linked with ring increases which produces repulsion effect
Related Questions to study
physics-
Shown in the figure is a circular loop of radius r and resistance R. A variable magnetic field of induction
is established inside the coil. If the key (K) is closed, the electrical power developed right after closing the switch is equal to

Shown in the figure is a circular loop of radius r and resistance R. A variable magnetic field of induction
is established inside the coil. If the key (K) is closed, the electrical power developed right after closing the switch is equal to

physics-General
physics-
The resistance in the following circuit is increased at a particular instant. At this instant the value of resistance is 10W. The current in the circuit will be now

The resistance in the following circuit is increased at a particular instant. At this instant the value of resistance is 10W. The current in the circuit will be now

physics-General
physics-
A conducting rod PQ of length L = 1.0 m is moving with a uniform speed v = 2 m/s in a uniform magnetic field
directed into the paper. A capacitor of capacity C = 10 mF is connected as shown in figure. Then

A conducting rod PQ of length L = 1.0 m is moving with a uniform speed v = 2 m/s in a uniform magnetic field
directed into the paper. A capacitor of capacity C = 10 mF is connected as shown in figure. Then

physics-General
Maths-
Let f(x) = 
Assertion (A): Fundamental period of f(x) is 2
Reason (R) : period of sin x and cos x is 2
Let f(x) = 
Assertion (A): Fundamental period of f(x) is 2
Reason (R) : period of sin x and cos x is 2
Maths-General
maths-
If (x1 ,y1) and (x2, y2) and ends of a focal chord of the parabola
= 4ax, then square of G.M. of x1 and x2 is-
If (x1 ,y1) and (x2, y2) and ends of a focal chord of the parabola
= 4ax, then square of G.M. of x1 and x2 is-
maths-General
physics-
A conductor ABOCD moves along its bisector with a velocity of 1 m/s through a perpendicular magnetic field of 1 wb/m2, as shown in fig. If all the four sides are of 1m length each, then the induced emf between points A and D is

A conductor ABOCD moves along its bisector with a velocity of 1 m/s through a perpendicular magnetic field of 1 wb/m2, as shown in fig. If all the four sides are of 1m length each, then the induced emf between points A and D is

physics-General
physics-
A square metallic wire loop of side 0.1 m and resistance of 1W is moved with a constant velocity in a magnetic field of 2 wb/m2 as shown in figure. The magnetic field is perpendicular to the plane of the loop, loop is connected to a network of resistances. What should be the velocity of loop so as to have a steady current of 1mA in loop

A square metallic wire loop of side 0.1 m and resistance of 1W is moved with a constant velocity in a magnetic field of 2 wb/m2 as shown in figure. The magnetic field is perpendicular to the plane of the loop, loop is connected to a network of resistances. What should be the velocity of loop so as to have a steady current of 1mA in loop

physics-General
physics-
A conducting wire frame is placed in a magnetic field which is directed into the paper. The magnetic field is increasing at a constant rate. The directions of induced current in wires AB and CD are

A conducting wire frame is placed in a magnetic field which is directed into the paper. The magnetic field is increasing at a constant rate. The directions of induced current in wires AB and CD are

physics-General
physics-
As shown in the figure a metal rod makes contact and complete the circuit. The circuit is perpendicular to the magnetic field with
If the resistance is
, force needed to move the rod as indicated with a constant speed of
is

As shown in the figure a metal rod makes contact and complete the circuit. The circuit is perpendicular to the magnetic field with
If the resistance is
, force needed to move the rod as indicated with a constant speed of
is

physics-General
physics-
As shown in the figure, P and Q are two coaxial conducting loops separated by some distance. When the switch S is closed, a clockwise current
flows in P (as seen by E) and an induced current
flows in Q. The switch remains closed for a long time. When S is opened, a current
flows in Q. Then the directions of
and
(as seen by E) are

As shown in the figure, P and Q are two coaxial conducting loops separated by some distance. When the switch S is closed, a clockwise current
flows in P (as seen by E) and an induced current
flows in Q. The switch remains closed for a long time. When S is opened, a current
flows in Q. Then the directions of
and
(as seen by E) are

physics-General
Maths-
A particle moves along a line by
then S is decreasing when t 
A particle moves along a line by
then S is decreasing when t 
Maths-General
maths-
Assertion: f(x) = ln
is an odd function.
Reason: Let f be a function with domain D such that
i) x
D
– x
D
ii) f(–x) = – f(x) and
iii) f (0) = 0 or f (0) is not defined
Then the function f(x) is an odd function
Assertion: f(x) = ln
is an odd function.
Reason: Let f be a function with domain D such that
i) x
D
– x
D
ii) f(–x) = – f(x) and
iii) f (0) = 0 or f (0) is not defined
Then the function f(x) is an odd function
maths-General
physics-
A conducting rod of length 2l is rotating with constant angular speed w about its perpendicular bisector. A uniform magnetic field
exists parallel to the axis of rotation. The e.m.f. induced between two ends of the rod is

A conducting rod of length 2l is rotating with constant angular speed w about its perpendicular bisector. A uniform magnetic field
exists parallel to the axis of rotation. The e.m.f. induced between two ends of the rod is

physics-General
physics-
A metallic square loop ABCD is moving in its own plane with velocity v in a uniform magnetic field perpendicular to its plane as shown in the figure. An electric field is induced

A metallic square loop ABCD is moving in its own plane with velocity v in a uniform magnetic field perpendicular to its plane as shown in the figure. An electric field is induced

physics-General
physics-
Two circular coils can be arranged in any of the three situations shown in the figure. Their mutual inductance will be

Two circular coils can be arranged in any of the three situations shown in the figure. Their mutual inductance will be

physics-General