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

DC generator by william Sturgeon in:

• 1894 A
• 1961 B
• 1834 C
• 1961 D

The working principle of transformer is.

• Self induction A
• Faraday's law B
• Mutual induction C
• Electromagnetic induction D

If we make magnetic field stronger the value of induced current is.

• Decreased A
• Increased B
• Vanishes C
• Remain constant D

Energy density in an inductor is.

• Directly proportional to magnetic field A
• Directly proportional to square of magnetic field B
• Inversely proportional to magnetic field C
• Inversely proportional to square of magnetic field D

When motor is just started, back emf is almost.

• Maximum A
• Zero B
• Minimum C
• Infinite D

By winding the coil around a less magnetic core, self induction.

• Will increase A
• Will decrease B
• Remain same C
• First increase then decrease 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

Self inductance of a long solenoid is given by

• 
  A
• 
  B
• 
  C
• None of the above D

If magnetic field is doubled then magnetic energy density becomes.

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

Energy stored in inductor is.

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

The direction of induced current is always so as to oppose the change which causes the current, this is the statement of

• Lenz's law A
• Faraday's law B
• Ampere's law C
• Coulomb's law D

Commentator was invented by

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

The jerks in D.C. motor are created by the use of.

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

split rings are used in

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

Lenz's law was given by Heinrich lenz in:

• 1894 A
• 1904 B
• 1854 C
• 1834 D

• 
  A
• 
  B
• 
  C
• 
  D