Electromagnetism

Question 1

Magnetic field of a solenoid

Answer 1

Strong within the solenoid, weak on the outside

Question 2

Why is there a force?

Answer 2

The current in the wire produces a magnetic field, and this magnetic field interacts with the magnetic field of the magnet to produce a force acting on the wire

Question 3

Wires carrying current in the same direction

Answer 3

Attraction

Question 4

Wires carrying current in opposite directions

Answer 4

Repulsion

Question 5

How to make magnetic field around wire stronger?

Answer 5

Increase current flowing through wire

Question 6

How to make magnetic field around solenoid stronger?

Answer 6

Increase current
Increase no. of turns per unit length
Place soft iron core within solenoid (concentrates magnetic field lines)

Question 7

How to increase magnitude of force produced in motor

Answer 7

1. Increase current
2. Use stronger magnet
3. Place soft iron core in coil of motor
4. Increase no. of turns in coil

Question 8

Purpose of split ring commutator

Answer 8

Allows current to flow smoothly
Reverses current in coil twice in every complete turn so that continuous rotation of coil can be produced
Prevents external circuit from getting entangled when coil is rotating

Question 9

Purpose of carbon brushes

Answer 9

Ensures continuous contact between split ring and external circuit