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प्रश्न
Name any two appliances which works on the phenomenon of magnetic effect of electric current.
Name any three appliances based on the magnetic effect of electric current.
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उत्तर
Ammeter, microphone, electric bell, galvanometer, loud speaker, electric generator, electric motor, telephone receiver, radio, stereo speaker.
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संबंधित प्रश्न
When the current is switched on through a wire, a compass needle kept nearby gets deflected from its north-south position. Explain.
Will the compass needle show deflection when the switch in the circuit shown by figure is closed?
Fill in the following blank with suitable words:
The magnetic effect of a coil can be increased by increasing the number of ........... increasing the ........... or inserting an ........... core.
The magnetic effect of current was discovered by:
(a) Maxwell
(b) Fleming
(c) Oersted
(d) Faraday
The direction of current flowing in the coil of an electromagnet at its two ends X and Y are as shown below:
What is the polarity of end X?
What is the polarity of end Y?
Name and state the rule which you have used to determine the polarities.
What device reverses the current?
The north pole of a long bar magnet was pushed slowly into a short solenoid connected to a galvanometer. The magnet was held stationary for a few seconds with the north pole in the middle of the solenoid and then withdrawn rapidly. The maximum deflection of the galvanometer was observed when the magnet was ______.
If fuse of 250 mA, 500 mA, 1 A, 5 A and 10 A were available, which one would be the most suitable for protecting an amplifier rated at 240 V, 180 W?
How should the electric lamps in a building be connected so that the switching on or off in a room has no effect on other lamps in the same building?
Observe the following diagram and choose the correct alternative:
(c) Considering the relationship in the first pair, complete the second paie :
AgCI : White :: CuI2 : ___________
(ii) Global warming is a desirable aspect of the intensified greenhouse effect.
Explain the magnetic field created by a current around a conductor from the figure.
What is that instrument which can detect the presence of electric current in a circuit?
Paheli does not have a night lamp in her room. She covered the bulb of her room with a towel at the night to get dim light. Has she taken the right step? Give one reason to justify your answer.
A wire with green insulation is usually the live wire of an electric supply.
The figure given below shows the magnetic field around the conductor. Study it and answer the questions:
- What changes are caused by increasing current?
- What do you see when the magnetic needle is kept a little away from the wire?
- In the second part of the figure, the iron filings arrange themselves in a circular manner around the wire. Why does this happen?
