Electricity and Circuits
1. Fill in the blanks :
(a) A device that is used to break an electric circuit is called _______________.
(b) An electric cell has _______________ terminals.
2. Mark 'True' or 'False' for following statements:
(a) Electric current can flow through metals.
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(b) Instead of metal wires, a jute string can be
used to make a circuit.
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(c) Electric current can pass through a sheet
of thermo Col.
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3. Explain why the bulb would not glow in the
arrangement shown in Fig. 9.13.
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4. Complete the drawing shown in Fig. 9.14 to
indicate where the free ends of the two wires
should be joined to make the bulb glow.
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5. What is the purpose of using an electric switch?
Name some electrical gadgets that have switches
built into them.
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6. Would the bulb glow after completing the circuit
shown in Fig. 9.14 if instead of safety pin we
use an eraser?
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7. Would the bulb glow in the circuit shown in Fig. 9.15?
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8. Using the "conduction tester" on an object it was found that the bulb begins to
glow. Is that object a conductor or an insulator? Explain.
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9. Why should an electrician use rubber gloves while repairing an electric switch
at your home? Explain.
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10. The handles of the tools like screwdrivers and pliers used by electricians for
repair work usually have plastic or rubber covers on them. Can you explain
why?
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