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 speed of rotation of a generator is doubled the output voltage will be.

• Remain same A
• Double B
• Four time C
• One half D

The unit of induced emf is

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

The Si unit of Mutual inductance is:

• VA^-1S^-1 A
• VAS^-1 B
• VSA^-1 C
• ASV^-1 D

In A.C. inductor behaves as

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

The motional emf is give by

• qvB A
• IBL B
• eBL C
• vBL D

When motor is just started, back emf is almost.

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

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

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

For step down transformer

• Ns>Np A
• Np > Ns B
• Ns = Np C
• Ns > > > Np D

What is the co-efficient of mutual inductance, when the magnetic flux changes by 2 x 10^-2 Wb, and change in current is 0.01 A?

• 2 H A
• 3 H B
• 1/2 H C
• Zero D

The device in the circuit that consume electrical energy are known as.

• Dissipaters A
• Generator B
• Load C
• Motors D

Mutual induction play role in.

• Generator A
• D.C. motor B
• Galvanometer C
• Transformer 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 mutual inductance of the coils depends upon.

• Stiffness of the coils A
• Density of coils B
• Material of coils C
• Geometry of the coils D

the core of transformer is laminated so reduce.

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

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