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

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

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

The motional emf developed in a conduction depends upon.

• Length A
• Orientation B
• Magnetic field C
• All of the above D

Lenz's law is a consequence of the law of conservation of

• Charge A
• Momentum B
• Energy C
• Angular momentum 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

Step up transfer has a transformation ratio of 3:2. What is the voltage in secondary , If voltage in primary is 30 V?

• 45 V A
• 15 V B
• 90 V C
• 300 V D

The magnitude of back emf:

• Increases with sped of motor A
• Decreases with speed of motor B
• Remains same  C
• None of above D

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

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

Transformer is used to change

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

The direction of induced current is always so as to oppose the change which causes the current is:

• Faraday's law A
• Lenz's  law B
• Ohm's law C
• Kirchhoff's 1st rule D

The Si unit of Mutual inductance is:

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

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 north pole of a magnet moves away from a metallic ring

• Clockwise A
• Anticlockwise B
• First clockwise and then anticlockwise C
• None of above D

The only difference between the construction of D.C and A.C is.

• Carbon burshes A
• Coil B
• Commutator C
• Magnetic field D

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