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प्रश्न
You have been provided with a solenoid AB.
(i) What is the polarity at end A?
(ii) Give one advantage of an electromagnet over a permanent magnet.
उत्तर
(i) North pole.
(ii) The electromagnet is a very strong magnet as compared to a permanent magnet.
APPEARS IN
संबंधित प्रश्न
The phenomenon of electromagnetic induction is
An induced current is produced when a magnet is moved into a coil. The magnitude of induced current does not depend on:
(a) the speed with which the magnet is moved
(b) the number of turns of the coil
(c) the resistivity of the wire of the coil
(d) the strength of the magnet
Describe one experiment to demonstrate the phenomenon of electromagnetic induction.
When Puja, a student of 10th class, watched her mother washing clothes in the open, she observed coloured soap bubbles and was curious to know why the soap bubbles appear coloured. In the evening when her father, an engineer by profession, came home, she asked him this question. Her father explained to her the basic phenomenon of physics due to which the soap bubbles appear coloured.
(a) What according to you are the values displayed by Puja and her father?
(b) State the phenomenon of light involved in the formation of coloured soap bubbles.
The following diagram shows a fixed coil of several turns connected to a center zero galvanometer G and a magnet NS which can move in the direction shown in the diagram.
- Describe the observation in the galvanometer if
- The magnet is moved rapidly,
- The magnet is kept still after it has moved into the coil
- The magnet is then rapidly pulled out the coil.
- How would the observation in (i) of part (a) change if a more powerful magnet is used?
Give an illustration of determining direction of induced current by using Lenz’s law.
A cylindrical bar magnet is kept along the axis of a circular coil. If the magnet is rotated about its axis, then ____________.
Which of the following phenomena makes use of electromagnetic induction?
AB is a coil of copper wire having a large number of turns. The ends of the coil are connected with a galvanometer as shown. When the north pole of a strong bar magnet is moved towards end B of the coil, a deflection is observed in the galvanometer.
- State the reason for using galvanometer in the activity and why does its needle deflects momentarily when magnet is moved towards the coil.
- What would be observed in the galvanometer in a situation when the coil and the bar magnet both move with the same speed in the same direction? Justify your answer.
- State the conclusion that can be drawn from this activity.
Will there be any change in the momentary deflection in the galvanometer if number of turns in the coil is increased and a more stronger magnet is moved towards the coil?
OR
What is electromagnetic induction? What is observed in the galvanometer when a strong bar magnet is held stationary near one end of a coil of large number of turns? Justify your answer.
