Advertisements
Advertisements
Question
What will be the effect on the working of an electric bell if instead of a direct current an alternating current is used?
Advertisements
Solution
If electric bell is connected to a.c. instead of d.c. then bell will ring intermittently.
RELATED QUESTIONS
principle of an electric motor ?
What is an electromagnet?
Describe briefly one way of producing an induced current in a coil. State one factor that determines the magnitude of induced e.m.f.
State the two properties of the magnetic lines of force around a circular coil.
A straight wire is held vertical and current is passed in it in the upward direction. A compass needle is kept near the wire in north of it. How is the needle deflected? What is the change in the deflection of the needle if the current in wire is reversed?
State the purpose of the iron core.
State the condition when an electric charge can give rise to a magnetic field.
The primary windings of a step-up transformer are usually made of thicker wire than the secondary. Explain.
A current-carrying solenoid is suspended so as to freely rotate in a horizontal plane. State in what direction will it rest. Give a reason for your answer.
or
When a solenoid that is carrying current is freely suspended, it comes to rest in a particular direction. Why does this happen?
Point out three differences between an electromagnet and a bar (or permanent) magnet.
