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

B2/2p is the expression of.

• Lenz's law A
• Magnetic energy B
• Magnetic energy density C
• Back emf D

When back emf in motor is zero, it draws.

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

The device in which induced emf is statically induced emf is:

• Transforms A
• AC generator B
• Alevator C
• Dynamo D

In D.C. generator, split rings act as.

• Capacitor A
• Commutator B
• Resistor C
• Inductor 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' s1ast rule 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

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

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

split rings are used in

• A.C. generator A
• A.C. motor B
• Transformer C
• D.C. motor D

When a coil is moved in a uniform magnetic field, an induced emf is produced due of change in

• Flux density A
• Electric flux B
• Magnetic flux C
• Magnetic field strength D

If D.C. input for step up transformer, the output is

• Zero A
• High B
• Low C
• May be high or low 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

SI unit of hennery which is.

• VSA-1 A
• VS-1 A B
• VS-1A-1 C
• VSA D

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

Which one is not present in A.C. generator.

• Armature A
• Magnet B
• Slip rings C
• Commutator D

The mutual inductance of the coils depends upon.

• Stiffness of the coils A
• Density of coils B
• Material of coils C
• Geometry of the coils D

Eddy current is one cause energy loss in

• A.C. generator A
• Transformer B
• D.C. motor C
• D.C. generator D

When motor is just started, back emf is almost.

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