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

Eddy current is one cause energy loss in

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

The negative sign with induced emf in Faraday's law is in accordance with

• Lenz's law A
• Amperes law B
• Boyle's law C
• Gauss law 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 jerks in D.C. motor are created by the use of.

• Armature A
• Commutators B
• Split rings C
• Source of emf D

Eddy current is produced when:

• A metal is light in varying magnetic field A
• A metal is kept in steady magnetic field B
• A circular coil is placed in a steady magnetic field C
• A current is passed through a circualr coil D

Commentator was invented by

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

What is the co-efficient of mutual inductance, when the magnetic flux changes by 2 x 10^-2 Wb, and change in current is 0.01 A?

• 2 H A
• 3 H B
• 1/2 H C
• Zero D

Transformer is used to change

• Electric power A
• Magnetic field B
• Alternating voltage C
• Phase of A.C. D

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

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

The motional emf depends upon the

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

The movement of conductor in magnetic field produces electrical current was discovered in:

• 1931 A
• 1731 B
• 1842 C
• 1831 D

The induced emf in a coil is proportional to:

• Magnetic flux through the coil A
• Rate of change of Magnetic flux through the coil B
• Area of the coil C
• Product of magnetic flux flux and area of the coil D

Output of D.C. motor is

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

Which one is not present in A.C. generator.

• Armature A
• Magnet B
• Slip rings C
• Commutator D

• 
  A
• 
  B
• 
  C
• 
  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

With the speed of motor, magnitude of back emf

• Remain same A
• Increase B
• Decrease C
• First increases then decreases D