1. Fill in the Blanks:
a) A device that is used to break an electric circuit is called a switch.
b) An electric cell has two (2) terminals.
2. Mark true or false for following statements:
a) Electric current can flow through metals. (TRUE)
b) Instead of metal wires a jute string can be used to make a circuit. (FALSE)
c) Electric current can pass through a thermocol. (FALSE)
3. Explain why the bulb would not glow in the arrangement shown below?
Answer- The bulb would not glow in the given arrangement because the handle of the screw driver is an insulator and will not allow the current to pass through it.
4. Complete the drawing shown in figure to indicate where the free ends of the two wires should be joined to make the bulb glow.
Answer- The complete figure will be as following:
5. What is the purpose of using an electric switch? Name some electric gadgets that have switches buit into them.
Answer- The purpose of switch is to easily make or break a circuit. Almost all electric gadgets have switches in therm For example Television, Refrigerator, Washing Machine etc.
6. Would the bulb glow after completing the circuit shown in figure?
Answer-
7. Would the bulb glow in the circuit shown below?
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.
Answer- The bulb begins to glow, which means that circuit is complete. The object is a conductor as it is allowing the current to pass through it.
9. Why should an electrician use rubber gloves while repairing an electric switch at your home? Explain.
Answer- The electrician should use rubber gloves while repairing an electric switch at our home because the rubber gloves are insulators and they will prevent any kind of electrical shock to the electrician working with electrical switch or circuit.
10. The handles of the tools like screw drivers and pliers used by electricians for repair work usually have plastic or rubber covers on them. Can you explain why?
Answer- The handles of the tools like screw drivers and pliers used by electricians for repair work usually have plastic or rubber covers on them because plastic and rubber are insulators and they provide safety to electricians by avoiding any kind of electric shock to them while working with electricity.
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