Question 1:
State the principle of an electric generator.
Answer:
An electric generator works on the principle of electromagnetic induction. It generates electricity by rotating a coil in a magnetic field.
Question 2:
Name some sources of direct current.
Answer:
Some sources of direct current are cell, DC generator, etc.
Question 3:
Which sources produce alternating current?
Answer:
AC generators, power plants, etc., produce alternating current.
Question 4:
Choose the correct option.
A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced current changes once in each
(a) two revolutions |
(b) one revolution |
(c) half revolution |
(d) one-fourth revolution |
Answer:
(c) When a rectangular coil of copper is rotated in a magnetic field, the direction of the induced current in the coil changes once in each half revolution. As a result, the direction of current in the coil remains the same.