3. Complete Activity 10.3 (Page 113). Make a circuit as shown in Fig. 10.10. Take about 10 cm long piece of nichrome wire and tie it between the nails. Touch the wire. Now switch on the current in the circuit by moving the switch to the ‘ON position. After a few seconds touch the wire. (Do not hold it for a long time.) Switch off the current. Touch the wire again after a few minutes. Make the necessary conclusions.
Answer: Activity 10.3 can be carried out as follows:
Aim: To examine if current has any effect on the nichrome wire.
Materials Required: Two iron nails, 10 cm long nichrome wire, switch, electric cell.
Procedure:
(i)Buy a 10 cm long nichrome wire from an electric repair shop or use a piece of discarded coil of an electric heater and tie it between the two nails.
(ii) Connect it to the switch and battery to complete the circuit.
(iii) Touch the wire with the switch ‘OFF’ and note what you feel.
(iv) Then let current flow in the circuit by moving the switch to ‘ON’ position and touch the wire after a few seconds. Note what you feel.
(v) Switch off the current and again touch the wire after a few minutes. Note what you feel.
Observations:
- Initially when the current is off’ the nichrome wire feels cool.
- When the current is switched on the wire feels hot when touched after a few seconds.
- Then when the current is turned off again the wire feels cool again after a few minutes.
Conclusions: Electric current heats up the nichrome wire and this is known as the heating effect of electric current.
“Make a circuit as shown in Fig. 10.10. Take about 10 cm long piece of nichrome wire and tie it between the nails. Touch the wire. Now switch on the current in the circuit by moving the switch to the ‘ON position. After a few seconds touch the wire. (Do not hold it for a long time.) Switch off the current. Touch the wire again after a few minutes. Make the necessary conclusions.” – Solved.
Related Links:
Solution to Extended Learning Problem 1
Solution to Extended Learning Problem 2
Solution to Extended Learning Problem 3
Solution to Extended Learning Problem 4
Solution to Activity 10.1
Solution to Activity 10.2
Solution to Activity 10.3
Solution to Activity 10.4
Solution to Activity 10.5
Solution to Activity 10.6
