PDF chapter test TRY NOW

Home-made switch:
 
Materials required:
 
Two drawing pins, a safety pin (or a paper clip), two wires and a small sheet of thermo Col or a wooden board.
Procedure:
  1. Insert a drawing pin into the ring at one end of the safety pin and fix it on the thermo Col sheet as shown in figure.
  2. Make sure that the safety pin can be rotated freely.
  3. Now, fix the other drawing pin on the thermo Col sheet in a way that the free end of the safety pin can touch it.
  4. The safety pin fixed in this way would be your switch in this activity.
switch off.jpg
Switch
 
Now, make a circuit by connecting an electric cell and a bulb with this switch as shown in figure. Rotate the safety pin so that its free end touches the other drawing pin.
 
YCIND_220726_4143_1.png
Circuit arrangement

What do you observe?
 
When the safety pin touches the free end, the bulb .
 
Now, move the safety pin away. Does the bulb continue to glow?
 
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