A circuit contains a battery, a variable resistor and a solenoid. The figure below shows the magnetic field pattern produced by the current in the solenoid.
a. State how the magnetic field pattern indicates regions where the magnetic field is stronger.
b. What happens to the magnetic field when the current in the circuit is reversed?
Answer
A magnetic field pattern indicates the strength and direction of a magnetic field.
- The field is strong in places where the number of magnetic field lines per unit area is high .
- The field is lower in strength where the number of magnetic field lines per unit area is low .
b. What happens to the magnetic field when the current in the circuit is reversed?
The reversal of the current direction would change the direction of the magnetic field.
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Direction of a magnetic field in a solenoid is found using the following rule:
Thus, if the direction of current is reversed, the direction of magnetic field is also reversed.
