Physics - Transfer of thermal energy
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1. May I know how do you make a fire alarm fitted with a simple bimetallic strip more sensitive to temperature rise?
I think you can do it by using a spiral bimetallic strip rather than a straight one as the curvy strip will trigger more movement. Can someone tell me another method? Thanks.
2. Let's say we have an electric bulb painted matt black on 1 half and silver on the other. The bulb is placed between a capillary tube which has 1 test tube placed in an inverted position and painted black on top of the 2 ends of the capillary tube. The capillary tube contains equal amount of water intially. The bulb is then switched on. Describe and explain what happens.
I think the matt black side of the bulb will emit more radiation than the silvered side. The radiation will then be absorbed by the black test tube situated on the capillary tube which is between the bulb. Water level on that side will decrease due to low pressure while the side of capillary tube nearer the silvered side of bulb will see an increase in water level due to high pressure...
Not sure whether this is right. But please help, thanks again.
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Originally posted by anpanman:
1. May I know how do you make a fire alarm fitted with a simple bimetallic strip more sensitive to temperature rise?
I think you can do it by using a spiral bimetallic strip rather than a straight one as the curvy strip will trigger more movement. Can someone tell me another method? Thanks.
2. Let's say we have an electric bulb painted matt black on 1 half and silver on the other. The bulb is placed between a capillary tube which has 1 test tube placed in an inverted position and painted black on top of the 2 ends of the capillary tube. The capillary tube contains equal amount of water intially. The bulb is then switched on. Describe and explain what happens.
I think the matt black side of the bulb will emit more radiation than the silvered side. The radiation will then be absorbed by the black test tube situated on the capillary tube which is between the bulb. Water level on that side will decrease due to low pressure while the side of capillary tube nearer the silvered side of bulb will see an increase in water level due to high pressure...
Not sure whether this is right. But please help, thanks again.
For 1), paint the strip black .
For 2), I am not too sure. A diagram will help out a lot.