Advertisements
Advertisements
Question
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.
Advertisements
Solution
Soft iron is used in all.
APPEARS IN
RELATED QUESTIONS
The diagram shows a coil wound around a U-shaped soft iron bar AB.
- What is the polarity induced at the ends A and B when the switch is pressed?
- Suggest one way to strengthen the magnetic field in the electromagnet.
- What will be the polarities at A and B if the direction of current is reversed in the circuit?
How will you make an iron bar electromagnet? Draw a diagram showing the polarities of the electromagnet?
Suppose you are given a long bar magnet and you are asked to break it into four small magnets. Draw diagrams showing the polarities of each broken part.
State two differences between an electromagnet and a permanent magnet.
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?
A straight current-carrying conductor is kept in a magnetic field. It Experiences a force. State three factors on which the magnitude of force Experienced by the conductor depends. Under what condition will the conductor Experience no force?
State two advantages of an electromagnet over a bar magnet.
What are the factors that govern the magnitude of force acting on a current carrying conductor which is freely suspended in a magnetic field?
