Second Year Physics Chapter 15 Online MCQ Test for 2nd Year Physics Chapter 15 Electromagnetic Induction Preparation

The unit of induced emf is

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

With the speed of motor, magnitude of back emf

• Remain same A
• Increase B
• Decrease C
• First increases then decreases D

A.C. Generator based upon the

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

The emf induced by the motion of a conductor across a magnetic field is called:

• Motional emf A
• Rotational emf B
• Induced emf C
• All of above D

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

• 1931 A
• 1731 B
• 1842 C
• 1831 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

The self induction emf is some times called.

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

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

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

When the back emf in a current is zero, it draws

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

Lenz's law deals with

• Magnitude of emf A
• Direction emf B
• Direction of induced current C
• Resistance D

Commentator was invented by

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

B2/2p is the expression of.

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

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

Energy density of an inductor is:

• UM=1/2μ_∘/B² A
• Um = 2μ_∘/B B
• UM = 1/2B²/μ_∘ C
• Um = 2B²/μ_∘ D

Energy stored in an inductor is:

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

Commutator was invented in

• 1834 A
• 1820 B
• 1840 C
• 1835 D