Physics FSC Part 2 Chapter 15 Online MCQ's Test

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

Electromagnetic induction is exactly according to law of:

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

A metal rod of 1 m is moving at a speed of 1 ms-1 in a direction making an angle 30 ^o with 0.5 T magnetic field . The emf produced is.

• 0.25 N A
• 2.5 N B
• 0.25 V C
• 2.5 V 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

A current generator device converts:

• Mechanical energy into chemical energy A
• Chemical energy into electrical energy B
• Mechanical energy into electrical energy C
• Both b and c 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

In self induction A coil is connected in__________ with battery and a rheostat.

• Parallel A
• Series B
• Both A and B 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

Eddy current is one cause energy loss in

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

A simple device that prevents the direction of current from changing is called.

• Commutator A
• Rotor B
• Armature C
• Detector D

A step up transformer is used 120 V line to provide 240 V. If primary coil has 100 turns the number of turns is secondary is.

• 50 A
• 100 B
• 150 C
• 200 D

The Si unit of Mutual inductance is:

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

The working principle of transformer is.

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

The mutual inductance between two coils depends upon their

• Size A
• Core material B
• Size, core material and separation C
• Separation D