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

The Lenz's law fulfils.

• Law of conservation of energy A
• Law of conservation of charge B
• Law of conservation of momentum C
• Kirchhoff's law D

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

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

When a coil is moved in a uniform magnetic field, an induced emf is produced due of change in

• Flux density A
• Electric flux B
• Magnetic flux C
• Magnetic field strength D

Mutual induction play role in.

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

In A.C. generator , when plane of coil is perpendicular to magnetic field, then output of generator is.

• NwAB A
• 2pi f B
• Maximum C
• Zero 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

The working principle of transformer is.

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

Unit of self inductance is

• Weber A
• Tesla B
• Henry C
• Farad D

Commutator was invented in

• 1834 A
• 1820 B
• 1840 C
• 1835 D

In A.C. inductor behaves as

• Capacitor A
• Resistor B
• Commutator C
• Transistor 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

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

Lenz's law deals with

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

The motional emf depends upon the

• Length of conductor A
• Speed of conductor B
• Strength of magnet C
• All of these D

Which of the following quantities remain constant in step up transformer?

• Current A
• Voltage B
• Power C
• Heat D

Mutual induction has a practical role in the performance of the.

• Radio choke A
• Transformers B
• A.C. Generator C
• D.C. Generator D

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

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