ELECTRIC CURRENT AND SIMPLE CIRCUITS
REVISION
1. Which property of a conducting wire is utilized in making
electric fuse?
2. Name the device used these days in place of electric fuses in
electrical circuits.
3. Fill in the blanks:
(i) Our body is a ________________ of electricity.
(ii) An electric cell produces electricity from the __________
___________ in it.
(iii) In an electric circuit a fuse is a _________ _______ to
prevent possible fire.
(iv) A combination of two or more cells is called a _________.
4. Unscramble the following words:
(i) TBTAYER
(ii) SFEU
(iii) HTRCO
(iv) HICWTS
5. 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.
6. Why are compact fluorescent lamps (CFLs) preferred over
electric bulbs?
7. Why is an electric fuse required in all electrical appliances?
8.Name two electric devices for each where
(i) heating effect of
current is used and
(ii) magnetic effect of current is used.
9. Why do we cover plug pin holes which are within the reach of
children with cello tape or a plastic cover when not in use?
10. 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.
11. How does the magnetic effect of electric current help in the
working of an electric bell? Explain with the help of a diagram.
12. Draw the symbols of the following circuit components.
(i) electric cell
(ii) switch in off position
(iii) electric bulb
(iv) battery
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