Question

Two $r_{1}$ resistances are connected in parallel in circuit X and in series in circuit Y. The batteries in the two circuits are identical and have zero internal resistance. Assume that the energy transferred to resistance A in circuit X within a certain time is W. The energy transferred to resistor B in circuit Y in the same time will be

• A. $r_{1}$
• B. $r_{2}$
• C. 2W
• D. 4W

Answer 1

Answer: (A)

$r_{1}$

Answer 2

:

In circuit X, both the resistances are in parallel. Therefore V is the same and, Power (energy transferred in unit time) is $\frac{V^{2}}{V} = W$

In circuit Y, both resistance are in series. Therefore

$V_{B} + V_{B}' = V$ or $V_{B} = V/2.$

In circuit Y, power supplied to

$B = \frac{(V/2)^{2}}{2} = \frac{V^{2}}{8} = \frac{W}{4}$