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

A.C. Generator based upon the

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

A step up transformer is used 120 V line to provide 240 V. If primary coil has 100 turns the number of turns is secondary is.

• 50 A
• 100 B
• 150 C
• 200 D

Efficiency of transformer does not affected by

• Input voltage A
• Core of transformer B
• Insulation between sheet C
• Resistance of coils 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 self induction emf is some times called.

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

EMF is induced due to change in

• Charge A
• Current B
• Magnetic flux C
• Electric field D

Mutual induction play role in.

• Generator A
• D.C. motor B
• Galvanometer C
• Transformer D

SI unit of hennery which is.

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

The north pole of a magnet is brought near a metallic ring. The direction of induced current in the ring will be:

• Antoclockwise A
• Clockwise B
• First Clockwise and then Antoclockwise C
• First anticlockwise and then Clockwise 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

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

• 100 J A
• 5 J B
• 20 J C
• Zero 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

Commentator was invented by

• Henry A
• Ousted B
• Maxwell C
• William sturgeon D

• 
  A
• 
  B
• 
  C
• 
  D

When a conductor moves across a magnetic field an emf is set up this emf is called.

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

Commutator was invented in

• 1834 A
• 1820 B
• 1840 C
• 1835 D