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

The Si unit of Mutual inductance is:

• VA^-1S^-1 A
• VAS^-1 B
• VSA^-1 C
• ASV^-1 D

Step up transfer has a transformation ratio of 3:2. What is the voltage in secondary , If voltage in primary is 30 V?

• 45 V A
• 15 V B
• 90 V C
• 300 V D

Self induction does not depend on

• Number of turns of the coil A
• Area of cross section of the core B
• Nature of material of the core C
• Current through inductor 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

When the back emf is zero, its draws.

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

B2/2p is the expression of.

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

Lenz's law is a consequence of the law of conservation of

• Charge A
• Momentum B
• Energy C
• Angular momentum D

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

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

Commutator was invented in

• 1834 A
• 1820 B
• 1840 C
• 1835 D

• 
  A
• 
  B
• 
  C
• 
  D

Which of the following converts electrical energy into mechanical energy.

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

The unit of induced emf is

• Ampere A
• Volt B
• Joule/coulomb C
• Both (b) and (c) D

When motor is just started, back emf is almost.

• Maximum A
• Zero B
• Minimum C
• Infinite 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

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

The magnitude of back emf:

• Increases with sped of motor A
• Decreases with speed of motor B
• Remains same  C
• None of above D

If a step up transformer were 100% efficient the primary and secondary winging's would have the same.

• Current A
• Power B
• Voltage C
• Direction of winding D