Page 124 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key
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4. Which of the following is not an effect of electric current?
(a) Heating effect (b) Chemical effect (c) Magnetic effect (d) Light effect
Ans: (d)
5. Which of the following is an insulator?
(a) Mercury (b) Glass (c) Copper (d) Silver
Ans: (b)
6. The full form of MCB is …………………… .
(a) Magnetic circuit breaker (b) Miniature circuit breaker
(c) Magnetic circuit box (d) Miniature circuit box
Ans: (b)
7. An …………………… is a safety device to prevent damage to an electric circuit when
excessive current flows through it.
(a) Battery (b) Resistance (c) Electric fuse (d) Electromagnet
Ans: (c)
8. The filament of the bulb is made of …………………… as it has high melting point.
(a) Tungsten (b) Copper (c) Gold (d) Lead
Ans: (a)
B. Fill in the blanks.
1. Our body is a ...................... of electricity.
Ans: conductor
2. The combination of two or more cells is called a ...................... .
Ans: battery
3. The safety device based on the heating effect of electric current is called ................. .
Ans: electric fuse
4. Electric current is a flow of ...................... .
Ans: electric charge
5. Water heaters have a ...................... that gets hot when current passes through it.
Ans: heating element
6. It is mandatory for various electrical products, such as electrical wires, switches,
electric motors, heaters and kitchen appliances, to carry the ...................... mark.
Ans: ISI
7. ...................... is a device based on magnetic effect of electric current.
Ans: Electromagnet
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