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

Lenz's law deals with

• Magnitude of emf A
• Direction emf B
• Direction of induced current C
• Resistance D

The self induction emf is some times called.

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

A.C is converted into D.C by

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

Efficiency of transformer does not affected by

• Input voltage A
• Core of transformer B
• Insulation between sheet C
• Resistance of coils 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

• 
  A
• 
  B
• 
  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

The Si unit of Mutual inductance is:

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

The working principle of transformer is.

• Self induction A
• Faraday's law B
• Mutual induction C
• Electromagnetic induction D

Output of D.C. motor is

• A.C. energy A
• Mechanical energy B
• Chemical energy C
• D.C. energy 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

A metal rod of 1 m is moving at a speed of 1 ms-1 in a direction making an angle 30 ^o with 0.5 T magnetic field . The emf produced is.

• 0.25 N A
• 2.5 N B
• 0.25 V C
• 2.5 V D

The  Lenz's law is also statement of:

• Law of conservation of mass A
• Law of conservation of charge B
• Law of conservation of energy C
• Law of conservation of momentum D

The motional emf depends upon the

• Length of conductor A
• Speed of conductor B
• Strength of magnet C
• All of these 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

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