Advertisements
Advertisements
Question
Name and state the rule by which polarity at the ends of a current carrying solenoid is determined.
Advertisements
Solution
The name of the rule is clock rule and it states. “If we look at the face of the loop and the direction of the current is anticlockwise, the direction of the magnetic field is north. If the direction of the current is clockwise, the direction of the magnetic field is south.”
APPEARS IN
RELATED QUESTIONS
The diagram shows a coil wound around a U shape soft iron bar AB.
1) What is the polarity induced at the ends A and B when the switch is pressed?
2) Suggest one way to strengthen the magnetic field in the electromagnet
3) What will be the polarities at A & B if the direction of current is reversed in the circuit?
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 of core in (a) an electric bell, (b) electromagnet, (c) a d.c. motor, (d) an a.c. generator and (e) a transformer.
What is an electromagnet?
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 factors that can increase the speed of rotation of the coil in a D.C. motor.
State the principle of a D. C. motor.
What is dynomo (a.c. generator)? State the principle on which it works.
