2. Complete Activity 10.2 (Page 112). Take an electric cell, a bulb, a switch and connecting wires. Make an electric circuit as shown in Fig. 10.9. This activity has to done using only one cell. Keep the switch in the ‘OFF’ position. Does the bulb glow? Touch the bulb. Now move the electric switch to the ‘ON’ position and let the bulb glow for a minute or so. Again touch the bulb. Do you feel any difference? After moving the switch back to the ‘OFF’ position, touch the bulb again. Make the necessary conclusions.
Answer:
Activity 10.2 can be carried out as follows:
Aim: To examine the effect electric current has on the bulb.
Materials Required: Electric cell, bulb, switch, connecting wires, hand.
Procedure:
(i) Take the electric cell, a bulb, a switch and connecting wires and make the electric circuit shown in Fig, 10.9. Use only one cell.
(ii) Keep the switch in the ‘OFF’ position. Observe if the bulb glows and note what you feel when you touch the bulb.
(iii) Now move the switch to the ‘ON’ position and let the bulb glow for around a minute. Again touch the bulb and note if you feel any change this time.
(iv) Move the switch back to ‘OFF’ position and touch the bulb again. Note what you feel.
(v) Make the necessary conclusions based on your observations in (ii), (iii) and (iv).
Observations:
- When the switch is ‘OFF’ the bulb does not glow and the bulb feels cold when touched.
- When the switch is ‘ON’ the bulb glows and after a minute it feels warm when touched.
- When the switch is moved back to ‘OFF’ position the bulb feels cool again after a while.
Conclusions: We conclude that electric current generates heat and this is known as the heating effect of electric current.
“Take an electric cell, a bulb, a switch and connecting wires. Make an electric circuit as shown in Fig. 10.9. This activity has to done using only one cell. Keep the switch in the ‘OFF’ position. Does the bulb glow? Touch the bulb. Now move the electric switch to the ‘ON’ position and let the bulb glow for a minute or so. Again touch the bulb. Do you feel any difference? After moving the switch back to the ‘OFF’ position, touch the bulb again. 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
