2nd Year Physics Chapter 15 Online MCQ Test for 12th Class Physics Chapter 15 (Electromagnetic Induction)

When motor is just started, back emf is almost.

• Maximum A
• Zero B
• Minimum C
• Infinite 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

Eddy current is produced when:

• A metal is light in varying magnetic field A
• A metal is kept in steady magnetic field B
• A circular coil is placed in a steady magnetic field C
• A current is passed through a circualr coil 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

Lenz's law deals with

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

Electromagnetic induction is exactly according to law of:

• Momentum A
• Charge B
• Energy C
• Mass 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

If we make magnetic field stronger the value of induced current is.

• Decreased A
• Increased B
• Vanishes C
• Remain constant D

The mutual inductance between two coils depends upon their

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

• 
  A
• 
  B
• 
  C
• 
  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 device in which induced emf is statically induced emf is:

• Transforms A
• AC generator B
• Alevator C
• Dynamo D

The negative sign with induced emf in Faraday's law is in accordance with

• Lenz's law A
• Amperes law B
• Boyle's law C
• Gauss law 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' s1ast rule D

One henry is equal to

• 1 ohm x 1 sec A
• 1 ohm x 1 hertz B
• 1 ohm x 1 metre C
• All of above D

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

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

If force in the direction of velocity of conductor,  then induced current is directed,

• Anti clockwise A
• Clock wise B
• At equilibrium C
• None of above D