NCERT Solutions for Class 7 Science Chapter 14

CBSE NCERT Solutions for Class 7 Science Chapter 14 Electric Current and its Effects in English and Hindi Medium are given below to use online or download in PDF format. If users are facing any problem to download contents, please Contact Us for the help. We are here to help you as much as possible without any charge.

1. When a switch is in OFF position,
(i) circuit starting from the positive terminal of the cell stops at the switch.
(ii) circuit is open.
(iii) no current flows through it.
(iv) current flows after some time.
Choose the combination of correct answer from the following.
(a) all are correct
(b) (ii) and (iii) are correct
(c) only (iv) is correct
(d) only (i) and (ii) are correct.

2. Choose the statement which is not correct in the case of an electric fuse.
(a) Fuses are inserted in electric circuits of all buildings.
(b) There is a maximum limit on the current which can safely flow through the electric circuits.
(c) There is a minimum limit on the current which can safely flow in the electric circuits.
(d) If a proper fuse is inserted in a circuit it will blow off if current exceeds the safe limit.

3. Which of the following precautions need not be taken while using electric gadgets/appliances/circuit?
(a) We should never touch a lighted electric bulb connected to the mains.
(b) We should never experiment with the electric supply from the mains or a generator or an inverter.
(c) We should never use just any wire or strip of metal in place of a fuse.
(d) We should never turn the switch in ON position.

4. Paheli does not have a night lamp in her room. She covered the bulb of her room with a towel in the night to get dim light. Has she taken the right step? Give one reason to justify your answer.

5. Boojho made an electromagnet by winding 50 turns of wire over an iron screw. Paheli also made an electromagnet by winding 100 turns over a similar iron screw. Which electro magnet will attract more pins? Give reason.

1 (b)
2 (c)
3 (d)
4. No. The towel may burn due to the heat produced by the bulb. Besides, it will also result in wastage of electric energy.
5. Paheli’s electromagnet will attract more pins as it has more number of turns of wire on it and thus a stronger electromagnet.