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

A current generator device converts:

• Mechanical energy into chemical energy A
• Chemical energy into electrical energy B
• Mechanical energy into electrical energy C
• Both b and c D

The Direction of induced current is always so as to oppose the change which causes the current, is:

• Faraday's law A
• Lenz's law B
• Ohm's law C
• Kirchhoff' s1ast rule D

The rod of unit length is moving at 30 o through a magnetic field of 1 T. If the velocity of rod is 1 m/s, then induced emf in the rod will be given by

• I V A
• 0.25 V B
• 0.5 V C
• 0.6 V D

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

• 1931 A
• 1731 B
• 1842 C
• 1831 D

The motional emf is give by

• qvB A
• IBL B
• eBL C
• vBL D

In self induction A coil is connected in__________ with battery and a rheostat.

• Parallel A
• Series B
• Both A and B C
• None of above D

the core of transformer is laminated so reduce.

• Magnetic loss A
• Hysteresis loss B
• Eddy current loss C
• Electric loss D

• 
  A
• 
  B
• 
  C
• 
  D

Electromagnetic induction is exactly according to law of:

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

The magnitude of motional emf is given by

• 
  A
• 
  B
• 
  C
• 
  D

If D.C. input for step up transformer, the output is

• Zero A
• High B
• Low C
• May be high or low D

B2/2p is the expression of.

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

For inducing emf in a coil the basic requirement is that:

• Flux should link the coil A
• Change in flux should link the coil B
• Coil should form a closed loop C
• Both (b) and (c) are true D

EMF is induced due to change in

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

When a motor is over loaded then the magnitude of back emf.

• Increases A
• Decreases B
• Remain constant C
• Zero D

Efficiency of transformer does not affected by

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