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

For step down transformer

• Ns>Np A
• Np > Ns B
• Ns = Np C
• Ns > > > Np 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 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

Eddy current is one cause energy loss in

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

Commutator was invented in

• 1834 A
• 1820 B
• 1840 C
• 1835 D

A.C. Generator based upon the

• Lenz's law A
• Maxwell's relation B
• Faradays law of electromagnet induction C
• Mutual induction D

SI unit of hennery which is.

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

The motional emf developed in a conduction depends upon.

• Length A
• Orientation B
• Magnetic field C
• All of the above D

A.C is converted into D.C by

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

Energy stored in inductor is.

• 1/2 L I² A
• 1/2 LI B
• 1/2 L2I C
• 1/2 L2I2 D

The self induction emf is some times called.

• Motional emf A
• Constant emf B
• Back emf C
• Variable emf D

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

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

If 10 A current passes through 100 mH inductor, then energy stored is.

• 100 J A
• 5 J B
• 20 J C
• Zero D

In a coil current change from 2 to 4 A in .05 s . If the average induced emf is 8 V then coefficient of self-inductance is:

• 0.2 henry A
• 0.1 henry B
• 0.8 henry C
• 0.04 henry D

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

• Capacitor A
• Commutator B
• Resistor C
• Inductor D

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