question_answer

A current of 3A flows through the 20, resistor shown in the circuit. The power dissipated in the 50 resistor is:

A) 4W                  

B) 2W     

C) 1W                  

D) 5W

Correct Answer: D

Solution :

[d] \[{{V}_{ab}}=6V\] \[{{V}_{ab}}={{V}_{cd}}={{V}_{ef}}\]                      (parallel combination) \[{{V}_{cd}}=6V\] \[I\times 4=6\] \[I\times 1.5A\] \[{{V}_{ef}}=I\times (5\times 1)\] \[6=I\times 6\] \[I\times 1A\] Power dissipated \[(5\Omega )={{I}^{2}}R\] \[={{(1)}^{2}}\times 5\] \[=5\,Watt\]