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

The unit of induced emf is

• Ampere A
• Volt B
• Joule/coulomb C
• Both (b) and (c) D

Commutator was invented by:

• William bills A
• William Gates B
• William tells C
• William Sturgeon D

Efficiency of transformer does not affected by

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

1 Henry =

• VSA^-1 A
• VS^-1A^-1 B
• V^-1SA C
• VSA^-2 D

Electromagnetic induction obeys law of conservation

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

The magnitude of motional emf is given by

• 
  A
• 
  B
• 
  C
• 
  D

The  Lenz's law is also statement of:

• Law of conservation of mass A
• Law of conservation of charge B
• Law of conservation of energy C
• Law of conservation of momentum D

The self induction emf is some times called.

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

Transformer is used to change

• Electric power A
• Magnetic field B
• Alternating voltage C
• Phase of A.C. D

Eddy current is one cause energy loss in

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

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

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

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

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

• Lenz's law A
• Faraday's law B
• Ampere's law C
• None of these 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

Lenz's law was given by Heinrich lenz in:

• 1894 A
• 1904 B
• 1854 C
• 1834 D

If magnetic field is doubled then magnetic energy density becomes.

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