Q. 203.7( 3 Votes )
State the three factors on which the heat produced by an electric current depends.
(i) the square of the current (I2)
(ii) resistance of wire (R)
(iii) time (t) for which current is passedSince the heat produced is directly proportional to the square of current,
H ∝ I2,
if the current is doubled, the heat produced will become four times and if the current is halved, the heat generated will become one-fourth.
Since the heat produced in a wire is directly proportional to the resistance,
H ∝ R, if the resistance is doubled, then the heat produced will also get doubled and if the resistance ishalved, the heat produced will also be halved. This means that a given current will produce more heat in a high resistance wire than a low resistance wire.
Since the heat produced in a wire is directly proportional to the time for which current flowsH ∝ t,
if the current is passed through a wire for double the time, then the heat produced is doubled and if the time is halved, the heat produced is also halved.
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i. In a household electric circuit different appliances are connected in parallel to one another. Give two reasons.
ii. An electrician puts a fuse of rating 5A in that part of domestic electrical circuit in which an electrical heater of rating 1.5 kW, 220 V is operating. What is likely to happen in this case and why? What change, if any, needs to be made?Xam idea - Science