2nd Year Physics Chapter 15 Online MCQ Test for 12th Class Physics Chapter 15 (Electromagnetic Induction)

In self induction A coil is connected in__________ with battery and a rheostat.

• Parallel A
• Series B
• Both A and B C
• None of above D

Induced emf in A.C. generator can be increased by

• Decreasing area of coil A
• Decreasing magnetic field B
• Increasing area of coil C
• Slowing down speed of coil D

If the north pole of a magnet moves away from a metallic ring

• Clockwise A
• Anticlockwise B
• First clockwise and then anticlockwise C
• None of above D

If speed of rotation of a generator is doubled the output voltage will be.

• Remain same A
• Double B
• Four time C
• One half D

Mutual induction has a practical role in the performance of the.

• Radio choke A
• Transformers B
• A.C. Generator C
• D.C. Generator D

When the back emf in a current is zero, it draws

• Zero current A
• Maximum current B
• Minimum current C
• Steady average current D

The direction of induced current is always so as to oppose the change which causes the current is:

• Faraday's law A
• Lenz's  law B
• Ohm's law C
• Kirchhoff's 1st rule D

Lenz's law was given by Heinrich lenz in:

• 1894 A
• 1904 B
• 1854 C
• 1834 D

Electromagnetic induction is exactly according to law of:

• Momentum A
• Charge B
• Energy C
• Mass D

A.C is converted into D.C by

• Dynamo A
• Rectifier B
• Motor C
• Transformer D

When motor is just started, back emf is almost.

• Maximum A
• Zero B
• Minimum C
• Infinite D

The current induced can be increased by:

• Using a stronger magnetic field A
• Moving the loop faster B
• Replacing the loop bay coi of many turns C
• All of above D

• Lenz's law A
• Faraday's law B
• Ampere's law C
• None of these D

The direction of induced current is always so as to oppose the change which causes the current, this is the statement of

• Lenz's law A
• Faraday's law B
• Ampere's law C
• Coulomb's law D

The negative sign with induced emf in Faraday's law is in accordance with

• Lenz's law A
• Amperes law B
• Boyle's law C
• Gauss law D

Electric current produces magnetic field, was suggested by.

• Faraday A
• Oersted B
• Henry C
• Lenz D

A simple device that prevents the direction of current from changing is called.

• Commutator A
• Rotor B
• Armature C
• Detector D