Magnetic Fields (Edexcel International A Level Physics)

A carriage on a roller coaster ride travels along a horizontal track towards a vertical tower, as shown.

(3)

Explain why the fin will leave the gap with a much slower speed than it entered the gap.

Faraday’s law can be written as

State the name of the term and its unit.

The magnetic flux density B perpendicular to the plane of the coil varies with time t as shown below.

Determine the maximum e.m.f. across the coil.

Maximum e.m.f. = ..............................

Some electric motor designs rely on electromagnetic induction.

A laboratory demonstration of the principle of an induction motor is shown.
An aluminium disc is free to rotate and is initially stationary. A powerful magnet is moved around the disc in the direction of the arrow, without touching the disc.

A student suggests that the disc will start to rotate as the magnet is moved and that the disc will rotate in the same direction as the movement of the magnet.

Discuss this suggestion.

In 1821, Michael Faraday made what is believed to be the first electric motor.

The stiff wire was suspended freely from a stand. The mercury completed an electrical circuit, which included the wire. When there was a current in the wire, the wire moved around the magnet.

Angular velocity = .....................................

When the current in the wire is 1.1 A, the wire is at an angle of 10° to the vertical. 

The length of the wire in the horizontal magnetic field is 3.5 cm.

Determine the force on the wire. 
magnetic flux density = 0.053 T