Electromagnetic Induction

Which of the following explains Electromagnetic Induction?

• Emf is induced when there is a change in electric flux through a conductor

• Emf is induced when there is a change in magnetic flux through a conductor

• Current is induced when the voltage changes through a conductor

• Voltage is induced when the current changes through a conductor

What is the magnetic flux linked with the plane?

• BA cos theta

• BA sin theta

• 2BA cos theta

• 2BA sin theta

State Lenz Law

• The induced current opposes magnetic flux

• The emf opposes change in magnetic flux

• The direction of induced current opposes in magnetic flux

• The direction of induced current opposes the change in magnetic flux

A magnet move from Q to P.

Which of the following statement is not true?

• The galvanometer deflects when magnet is brought near solenoid

• Induced current flows from X to Y when magnet approaching the solenoid

• Galvanometer shows maximum deflection when magnet at center of solenoid

• P is north when magnet is moved away from end P to the left

Which statement is not true?

• The induced current flows from M to C

• The emf induced in the rod is Blv

• The end C of the rod is at higher potential

• The free electrons in the rod experiences upward magnetic force

The current in the wire on the left increases at constant rate. What happens to the square coil on the right?

• Constant current is induced in clockwise direction

• Constant current is induced in anticlockwise direction

• Current is induced clockwise and increases with time

• Current is induced anticlockwise and increases with time

The induced current generated by a dynamo is affected by the following except

• Cross-sectional area of coil

• Number of turns of coil

• Speed of rotation

• Magnetic field strength

• Electric field strength

A current passes through a coil in a circuit as shown in the diagram. A back emf is induced as shown. Which of the following is true?

• The current is constant

• The current is decreasing

• The current is increasing

• A current is induced in the same direction

• A current is induced in the opposite direction

The current in primary coil decreases from 12A to zero in 58 ms. If the mutual inductance is 38.8 mH, calculate the induced emf in secondary coil.

• 12 V

• 8 V

• 4 V

• 2 V

What is the equation for energy in an inductor?

• 1/2 LI^2

• 1/2 LI

• BLv

• NBA