[QUIZ] Electromagnetic Induction

Figure below shows the side view of a circular coil of N turns and area A in a magnetic field B. If the normal to the plane of the coil makes an angle  with the magnetic field, the magnetic flux through the coil is

• NBA cos α

• NBA sin α

• BA cos α

• BA sin α

All of the following statements are true about magnetic flux except

• it is independent of surface area.

• it is the product of the normal component of the surface area with magnetic flux density.

• it is zero if the magnetic field is parallel to the surface.

• it represents the total magnetic field lines through a surface.

____________law states that the direction of the induced current is such that it always _______ ___ the change producing it.

• Lenz's Law, oppose

• Faraday's Law, oppose

• Lez's Law, follow

• Faraday's Law, follow

Which law states that the induced current is proportional to the change of magnetic flux?

• Lenz's law

• Ampere's law

• Faraday's law

• Gauss' law

The bar magnet is moved towards the coil and is then brought to stop. How the reading of ammeter changes during this process?

• The needle deflects to the right then left

• The current is increasing

• The current flows then become zero

• No deflection at all times during process

A coil is positioned with its center aligned to the bar magnet.  Which movement of the magnet will not produce an induced emf in the coil?

• 
• 
• 
• 

The galvanometer connected to a solenoid is experiencing a deflection to the left. What might be happening?

• The bar magnet is moving to the left, getting away from the stationary solenoid.

• The bar magnet is moving to the right, getting nearer to the stationary solenoid.

• The solenoid is moving to the left together with the bar magnet at the same speed.

• The solenoid is moving to the left, getting nearer to the stationary bar magnet.

How is the energy stored in an inductor when a current is flowing through it?

• Stored in the magnetic field created by the current.

• Stored in the electric field created by the current.

• Stored in the current flowing though the inductor.

• Stored in the power supply by directing the current back to the power supply.

Which of the following factors does not affect the inductance of a coil?

• The number of turns of the coil

• The current flows in the coil

• The length of the coil

• The cross-sectional area of the coil

The symbol and units of inductors are

• L (Henrys)

• C (Conductance)

• F (Flux)

• C (Farads)