Paheli took a wire of length 10 cm. Boojho took a wire of 5 cm of the same material and thickness. Both of them connected the wires as shown in the circuit given in Figure 14.4. The current flowing in both the circuits is the same.

(i) Will the heat produced in both the cases be equal? Explain.


(ii) Will the heat produce be the same if the wires taken by them are of equal lengths but of different thickness? Explain.


(i) No, as we know that resistance is directly proportional to length & H=I2RT where H is the heat/energy; I am current; R is the resistance and T is the time. Since Paheli has a wire which of larger length; hence it will increase more resistance. As current is the same in both the cases, so deciding factor for heat produced is resistance. Hence, Paheli circuit will produce more heat.

(ii) No, as we know that resistance is directly proportional to length and inversely proportional to area. Moreover, H=I2RT where H is the heat/energy; I am the current; R is the resistance and T is the time. Since the wire having more thickness will have less resistance, so less heat will be produced.


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