Question

The power dissipated in the circuit shown in the figure is 30W. The value of R is

• A. 20Ω
• B. 15Ω
• C. 10Ω
• D. 30Ω

Hint:

Total power in parallel circuits equals sum of powers in each branch.

Answer 1

The Correct Option is C

Step 1: Both resistors are in parallel across 10V.
Step 2: P=V²((1)/(R)+(1)/(5))
Step 3: 30=100((1)/(R)+0.2) (1)/(R)=0.1 R=10Ω