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प्रश्न
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.
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उत्तर
No, the towel may burn due to the heat produced by the bulb. Besides, it will also result in the wastage of electric energy. She could have used a lamp shade.
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संबंधित प्रश्न
An electromagnet does not attract a piece of iron.
Do you think an electromagnet can be used for separating plastic bags from a garbage heap? Explain.
The magnetic effect of current was discovered by:
(a) Maxwell
(b) Fleming
(c) Oersted
(d) Faraday
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 The magnet was held stationary for a few seconds with the north pole in the middle of the solenoid and then withdrawn rapidly.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 ______.
Observe the following diagram and choose the correct alternative:

Why do we cover plug pin holes which are within the reach of children with cellotape or a plastic cover when not in use?
______ are also used to remove splinters of steel or iron in hospitals dealing with eye injuries.
______ cells cannot be recharged after use.
An electric bell contains an ______, consisting of coils of insulated wire wound around
iron rods.
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?
