University:
University of Cambridge
Course:
0625 IGCSE | Physics
Academic year:

2023
Views:

15

Pages:

3
Author:

anon

IGCSE Coordinated Science: Magnetic Effect of a Current Magnetic Effect of a Current B = magnetic field I = current The magnitude of the magnetic field generated by a straight wire carrying current is dependent on two factors: 1. The strength of current. The stronger the current, the stronger the magnetic field is. 2. The distance from the wire. The further you are from the center of the wire, the weaker the magnetic field becomes. A solenoid is basically a wrapped coil of wire. The magnetic field it produces is similar to a bar magnet: The strength of a magnetic field produced by a solenoid is dependent on 3 factors: 1. The amount of turns that the coil makes. The more turns, the stronger the magnetic field. 2. The strength of current flowing. The stronger the current, the stronger the magnetic field is. 3. The radius of the coil. The smaller the radius, the stronger the magnetic field. Describe the effect on the magnetic field of changing the magnitude and direction of the current The strength of the current is proportional to the strength of the magnetic field. If one increases, so does the other. When you change the direction of the current, the polarity of the magnetic field changes as well. So basically, the north and south pole of the magnetic field is reversed/swapped whenever you reverse the direction of the current. Describe applications of the magnetic effect of current, including the action of a relay. One way that the magnetic effects of a current are applied is in the use of the circuit breakers. You know that the current flowing in a circuit is proportional to the strength of the magnetic field it generates. So in circuit breakers, when the current flowing gets too strong, the electromagnet becomes strong enough that it releases a latch, which in turns moves the contacts apart and opens the circuit. In relays, an electromagnet is used to move the contact from one circuit to another. The strength and the direction of the current can be used to control the magnetic field the electromagnet generates which controls which circuit the contact is touching.