Question

In the following circuits (Figure), heat produced in the resistor or combination of resistors connected to a 12 V battery will be

(i)	(ii)	(iii)

Options

• same in all the cases

• minimum in case (i)

• maximum in case (ii)

• maximum in case (iii)

Answer 1

maximum in case (iii)

Explanation - 

Heat produced in time (t) is given by

Heat (H) = `"V"^2/"R" xx "t"`

where, V = potential difference
R = Net resistance of the circuit
t = time

`"R"_(1"net") = 2Ω`

`"R"_(2"net") = 2Ω + 2Ω = 4Ω`

`"R"_(3"net") = (2xx2)/(2+2) = 1Ω`

Since, R_3net is minimum so heat produced will be maximum in case (iii).