Physics for IGCSE & O level - Magnets And Currents (Section 12)
1
Which device uses an electromagnet to open and close a circuit?
2
In a step-down transformer, the number of turns in the primary coil is:
Answer(B)
More than the secondary coil.
3
The equation that relates voltage, current, and power is:
4
How is the strength of an electromagnet increased?
5
Answer(A)
By using a small current to control a much larger current.
6
What is the term for a coil of wire that is free to rotate in a magnetic field in an electric motor?
7
Which of the following is a component of a simple electric motor?
