Q. Two wires A & B of the same material and length , have their cross-sectional area in the ratio - 1:4. What should be the ratio of heat produced in these wires, if the voltage applied is the same across?

Asked by Bhavya Garg | 30th Apr, 2011, 11:52: PM

Expert Answer:

A/C to Joule's law of heating;
H = I2 Rt = V2 t / R
So, voltage remaining same for two wires, the heat produced is inversely proportional to the resistance of the wire.
Now, R = ? l/a
Therefore, H = V2 t / (? l/a) = V2 at / ? l
Hence, Heat produced in wire A / heat produced in wire B = 1/4

Answered by  | 1st May, 2011, 05:05: PM

Queries asked on Sunday & after 7pm from Monday to Saturday will be answered after 12pm the next working day.