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

Which of the following converts electrical energy into mechanical energy.

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

• Lenz's law A
• Faraday's law B
• Ampere's law C
• None of these 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 winding of the electromagnet in motor are usually called.

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

• 
  A
• 
  B
• 
  C
• 
  D

When back emf in motor is zero, it draws.

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

Lenz's law deals with

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

Energy stored in inductor is.

• 1/2 L I² A
• 1/2 LI B
• 1/2 L2I C
• 1/2 L2I2 D

The induction can be increased by winding the wire around a core made of.

• Copper A
• Silicon B
• Iron C
• Aluminum D

Electric current produces magnetic field, was suggested by.

• Faraday A
• Oersted B
• Henry C
• Lenz 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

Commutator was invented in

• 1834 A
• 1820 B
• 1840 C
• 1835 D

A 50 mH coil carries a current of 2.0 a , then energy stored in tis magnetic field is.

• 0.1 J A
• 10 J B
• 100 J C
• 1000 J D

The motional emf depends upon the

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

If magnetic field is doubled then magnetic energy density becomes.

• Four times A
• Two times B
• Three times C
• Six times 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