Physics - Magnetic Fields Due To An Electeic Current

Question 1

Why does current create a magnetic field?

Answer 1

A magnetic field is created whenever an electrical charge is in motion

Question 2

What is the direction of magnetic field around a current carrying wire and of a solenoid?

Answer 2

• The right hand rule.
If current is moving away then magnetic field is in a clockwise direction
• In a solenoid if you wrap your fingers in the direction of current through the wires than your thumb will point in the direction of magnetic field (south to north)

Question 3

Factors affecting magnetic field strength of a current carrying wire

Answer 3

• The current flowing through the wire
• The amount of wire coils in a solenoid
• The presence of a metal core in a solenoid
• The resistance of the wire (a decrease in resistance increases current so increases magnetism

Question 4

Permanent magnets Vs electromagnets

Answer 4

A permanent magnet is made up of a material that is magnetized and creates it’s own persistent magnetic field, an electromagnet is a coil of wire that only has a magnetic field when there is a current flowing through the wire