Advertisements
Advertisements
प्रश्न
State three factors which govern the speed of rotation of an electric motor.
Advertisements
उत्तर
(i) The strength of current in the coil,
(ii) The number of turns in the coil,
(iii) The strength of the magnetic field.
APPEARS IN
संबंधित प्रश्न
State two ways of magnetising an iron piece?
Tick the most appropriate answer.
Which of the following methods is used to magnetize a magnetic without touching it by a magnet?
State three uses of an electromagnet?
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?
How does a magnetic field set up by a solenoid change when number of turns are increased?
Why is soft iron generally used as the core of the electromagnet?
State two advantages of an electromagnet over a bar magnet.
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.
(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.
