Page 55 - Innovator's Science-8

NCERT Textbook Questions (Solved)

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1. Fill in the blanks.
i. The solu on used in a Voltaic cell is called __________________
ii. A current carrying coil behaves like a __________________
Ans. i. Electrolyte ii. Magnet
2. Choose the correct op on:
i. Dry cells are less portable compared to Voltaic cells. (True/False)

ii. A coil becomes an electromagnet only when an electric current flows through it. (True/False)
iii. An electromagnet, using a single cell, a racts more iron paper clips than the same electromagnet
with a ba ery of 2 cells. (True/False)
Ans. i. False, ii. True, iii. False
3. An electric current flows through a nichrome wire for a short me.

i. The wire becomes warm.
ii. A magne c compass placed below the wire is deflected.
Choose the correct op on:
a. Only (i) is correct
b. Only (ii) is correct
c. Both (i) and (ii) are correct
d. Both (i) and (ii) are not correct
Ans. c. Both (i) and (ii) are correct

4. Match the following.
Column A Column B
i. Voltaic cell a. Best suited for an electric heater

ii. Electric Iron b. Works on magne c effect of electric current
iii. Nichrome wire c. Works on the hea ng effect of electric current
iv. Electromagnet d. Generates electricity by chemical reac ons
Ans. i. d, ii. c, iii. a, iv. b
5. Nichrome wire is commonly used in electrical hea ng devices because it.
i. is a good conductor of electricity.

ii. generates more heat for a given current.
iii. is cheaper than copper.
iv. is an insulator of electricity.
Ans. ii. Nichrome generates more heat for a given current

6. Electric hea ng devices (like an electric heater or a stove) are o en considered more convenient than
tradi onal hea ng methods (like burning firewood or charcoal). Give reasons to support this
statement, considering societal impact.

Ans. Tradi onal fuels like firewood or charcoal are not very convenient to use. They take up a lot of space to

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Science-8