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

The self induction emf is some times called.

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

EMF is induced due to change in

• Charge A
• Current B
• Magnetic flux C
• Electric field 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.C. Generator based upon the

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

In D.C. generator, split rings act as.

• Capacitor A
• Commutator B
• Resistor C
• Inductor D

Lenz's law presented in

• 1834 A
• 1934 B
• 1826 C
• 1836 D

B2/2p is the expression of.

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

Electromagnetic induction is exactly according to law of:

• Momentum A
• Charge B
• Energy C
• Mass D

Commentator was invented by

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

If force in the direction of velocity of conductor,  then induced current is directed,

• Anti clockwise A
• Clock wise B
• At equilibrium C
• None of above 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

• 
  A
• 
  B
• 
  C
• 
  D

Efficiency of transformer does not affected by

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

When the back emf is zero, its draws.

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

In case of inductor , energy is stored in the

• Electric field A
• Magnetic field B
• Potential field C
• Gravitational field D

Electromagnetic induction obeys law of conservation

• Charge A
• Energy B
• Momentum C
• Mass D