Advertisements
Advertisements
Question
State two factors on which the strength of induced e. m.f. depends.
Advertisements
Solution
(i) The time of change of magnetic flux, (ii) The strength of magnetic field.
RELATED QUESTIONS
You are given an iron nail, a torch cell, and a long piece of insulated copper wire. With the help of a labelled neat diagram, describe in steps how you will make the nail, an electromagnet.
Show with the aid of a diagram how a wire is wound on a U-shaped piece of soft iron in order to make it an electromagnet. Complete the circuit diagram and label the poles of the electromagnet.
Name the material used for making the armature of an electric bell. Give a reason for your answer.
What is an electric motor?
Describe briefly one way of producing an induced current in a coil. State one factor that determines the magnitude of induced e.m.f.
How does a magnetic field set up by a solenoid change when strength of current in the solenoid is decreased?
The primary windings of a step-up transformer are usually made of thicker wire than the secondary. Explain.
(i) A straight wire conductor passes vertically through a piece of cardboard sprinkled with iron filings. Copy the diagram and show the setting of iron filings when a current is passed through the wire in the upward direction and the cardboard is tapped gently. Draw arrows to represent the direction of the magnetic field lines.
(ii) Name the law which helped you to find the direction of the magnetic field lines.
State the function of a split ring in D.C. motor.
Which magnet will you use?
Iron is to be separated from trash.
