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

B2/2p is the expression of.

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

If a step up transformer were 100% efficient the primary and secondary winging's would have the same.

• Current A
• Power B
• Voltage C
• Direction of winding D

Lenz's law presented in

• 1834 A
• 1934 B
• 1826 C
• 1836 D

the core of transformer is laminated so reduce.

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

The motional emf developed in a conduction depends upon.

• Length A
• Orientation B
• Magnetic field C
• All of the above D

Step up transformer is used.

• Step up D.C. voltage A
• Step up A.C. voltage B
• Step up both A.C and D.C. C
• Step up A.C. current D

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

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

In a coil current change from 2 to 4 A in .05 s . If the average induced emf is 8 V then coefficient of self-inductance is:

• 0.2 henry A
• 0.1 henry B
• 0.8 henry C
• 0.04 henry D

When back emf in motor is zero, it draws.

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

• 
  A
• 
  B
• 
  C
• 
  D

Mutual induction play role in.

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

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

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

One henry is equal to

• 1 ohm x 1 sec A
• 1 ohm x 1 hertz B
• 1 ohm x 1 metre C
• All of above D

Energy stored in an inductor is:

• 1/2L²I A
• 1/2L²/I B
• _1/2LI² C
• 1/2LI 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 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

If the coil is wound on iron core, the flux through it.

• Decreases A
• Becomes zero B
• Increases C
• Remains constant D