Physics M.C.Q (1 Marks)

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 second. The charge that flows in the coil during this time is(a) 5.0 coulomb(b) 4.0 coulomb(c) 1.0 coulomb(d) 0.8 coulomb

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(a) Horizontal(b) Vertical(c) Clockwise(d) Anticlockwise

The unit of magnetic flux is

According to Faraday's law of electromagnetic induction(a) The direction of induced current is such that it opposes the cause producing it(b) The magnitude of induced e.m.f. produced in a coil is directly proportional to the rate of change of magnetic flux(c) The direction of induced e.m.f. is such that it opposes the cause producing it(d) None of the above

The direction of induced current is such that it opposes the very cause that has produced it. This is the law of(a) Lenz(b) Faraday(c) Kirchhoff(d) Fleming

Two different loops are concentric and lie in the same plane. The current in the outer loop is clockwise and increasing with time. The induced current in the inner loop then, is(a) Clockwise (b) Zero(c) Counter clockwise(d) In a direction that depends on the ratio of the loop radii

A 50 turns circular coil has a radius of 3 cm, it is kept in a magnetic field acting normal to the area of the coil. The magnetic field B  increased from 0.10 tesla to 0.35 tesla in 2 milliseconds. The average induced e.m.f. in the coil is(a) 1.77 volts(b) 17.7 volts(c) 177 volts(d) 0.177 volts

The direction of induced e.m.f. during electromagnetic induction is given by(a) Faraday's law(b) Lenz's law(c) Maxwell's law(d) Ampere's law

Lenz's law is consequence of the law of conservation of(a) Charge(b) Momentum(c) Mass (d) Energy

In electromagnetic induction, the induced charge in a coil is independent of(a) Change in the flux(b) Time(c) Resistance in the circuit(d) None of the above

A cylindrical bar magnet is kept along the axis of a circular coil. If the magnet is rotated about its axis, then(a)  A current will be induced in a coil(b)  No current will be induced in a coil(c)  Only an e.m.f. will be induced in the coil(d)  An e.m.f. and a current both will be induced in the coil

The current flowing in two coaxial coils in the same direction. On increasing the distance between the two, the electric current will(a)  Increase(b)  Decrease(c)  Remain unchanged(d)  The information is incomplete

Assertion :   An ac generator is based on the phenomenon of self-induction.
Reason     : In single coil, we consider self-induction only.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If assertion is false but reason is true.

Assertion :   Soft iron is used as a core of transformer.
Reason     : Area of hysteresis is loop for soft iron is small.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

Assertion :   A transformer cannot work on dc supply.
Reason     : dc changes neither in magnitude nor in direction.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

Assertion  :   A bar magnet is dropped into a long vertical copper tube. Even taking air resistance as negligible, the magnet attains a constant terminal velocity. If the tube is heated, the terminal velocity gets increased.
Reason     : The terminal velocity depends on eddy current produced in bar magnet.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

Assertion :   An artificial satellite with a metal surface is moving above the earth in a circular orbit. A current will be induced in satellite if the plane of the orbit is inclined to the plane of the equator.
Reason     : The current will be induced only when the speed of satellite is more than 8 km/sec.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

Assertion :   The induced emf in a conducting loop of wire will be non zero when it rotates in a uniform magnetic field.
Reason    : The emf is induced due to change in magnetic flux.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

Assertion  :   Lenz’s law violates the principle of conservation of energy.
Reason      : Induced e.m.f., opposes always the change in magnetic flux responsible for its production.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If assertion is false but reason is true.

Assertio  :   In the phenomenon of mutual induction, self induction of each of the coils persists.
Reason   : Self induction arises when strength of current in same coil changes. In mutual induction, current is changing in both the individual coils.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

Assertion  :   A spark occur between the poles of a switch when the switch is opened.
Reason      : Current flowing in the conductor produces magnetic field.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

Assertion  :   An aircraft flies along the meridian, the potential at the ends of its wings will be the same.
Reason     : Whenever there is change in the magnetic flux e.m.f. induces.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

Assertion :   When two coils are wound on each other, the mutual induction between the coils is maximum.
Reason     : Mutual induction does not depend on the orientation of the coils.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

Assertion  :   Self-inductance is called the inertia of electricity.
Reason      : Self-inductance is the phenomenon, according to which an opposing induced e.m.f. is produced in a coil as a result of change in current or magnetic flux linked in the coil.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

Assertion : The induced e.m.f. and current will be same in two identical loops of copper and aluminium, when rotated with same speed in the same magnetic field.
Reason : Induced e.m.f. is proportional to rate of change of magnetic field while induced current depends on resistance of wire.

Assertion :   Magnetic flux can produce induced e.m.f.
Reason     : Faraday established induced e.m.f. experimentally.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If assertion is false but reason is true.

A conducting ring of radius 1 meter is placed in an uniform magnetic field B of 0.01Telsa oscillating with frequency 100Hz with its plane at right angles to B. What will be the induced electric field(a) π volt/m(b) 2 volt/m(c) 10 volt/m(d) 62 volt/m