Second Year Physics Chapter 15 Online MCQ Test for 2nd Year Physics Chapter 15 Electromagnetic Induction Preparation

When back emf in motor is zero, it draws.

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

• 
  A
• 
  B
• 
  C
• 
  D

The emf induced by the motion of a conductor across a magnetic field is called:

• Motional emf A
• Rotational emf B
• Induced emf C
• All of above D

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

When a motor is over loaded then the magnitude of back emf.

• Increases A
• Decreases B
• Remain constant C
• Zero D

DC generator by william Sturgeon in:

• 1894 A
• 1961 B
• 1834 C
• 1961 D

Commutator was invented by:

• William bills A
• William Gates B
• William tells C
• William Sturgeon D

split rings are used in

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

Energy density in an inductor is.

• Directly proportional to magnetic field A
• Directly proportional to square of magnetic field B
• Inversely proportional to magnetic field C
• Inversely proportional to square of magnetic field D

For step down transformer

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

In A.C. generator , when plane of coil is perpendicular to magnetic field, then output of generator is.

• NwAB A
• 2pi f B
• Maximum C
• Zero D

The winding of the electromagnet in motor are usually called.

• Magnetic coils A
• Field coils B
• Electric coils C
• electric o electric coils D

A.C is converted into D.C by

• Dynamo A
• Rectifier B
• Motor C
• Transformer 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

A current generator device converts:

• Mechanical energy into chemical energy A
• Chemical energy into electrical energy B
• Mechanical energy into electrical energy C
• Both b and c D

If force in the direction of velocity of conductor,  then induced current is directed,

• Anti clockwise A
• Clock wise B
• At equilibrium C
• None of above D