Advertisements
Advertisements
प्रश्न
State two factors on which the strength of induced e. m.f. depends.
Advertisements
उत्तर
(i) The time of change of magnetic flux, (ii) The strength of magnetic field.
संबंधित प्रश्न
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?
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.
State two differences between an electromagnet and a permanent magnet.
Fill in the blanks by writing (i) Only soft iron, (ii) Only steel, (iii) Both soft-iron and steel for the material of core and/or magnet.
Electric bell ______.
Complete the following sentence :
On reserving the direction of current in a wire, the magnetic field produced by it gets _____.
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 condition when an electric charge can give rise to a magnetic field.
State two advantages of an electromagnet over a bar magnet.
What energy conversion takes place during the working of a d c motor?
State the principle of a D. C. motor.
