Question

Two resistors A and B of resistance 4 ohm and 6 ohm respectively are connected in parallel. The combination is connected across a 6 volt battery of negligible resistance. Calculate: (i) the power supplied by the battery, and (ii) the power dissipated in each resistor.

Answer 1

Equivalent Resistance, $R^{\prime }=(4\times 6)/(4+6)=24/10$
$R^{\prime }=2.4ohm$

We know that,
$I=V/R^{\prime }$
$I=6/2.4$
$I=2.5A$

The power is given by,
$P=I^2{R}^{\prime }$
$P={2.5}^2\times 2.4$
$P=15Watt$.
Power dissipation, in first resistor,

$P_1=V^2/R_1$
$P_1=6^2/4$
$P_1=9Watt$.
Power dissipation, in second resistor

$P_2=V^2/R_2$

$P_2=6^2/6$
$P_2=6Watt$.