In the circuit shown, the current through $ 8 \Omega $ is same before and after connecting $ E$. The value of $ E$ is
Step 1: Given data
The current through is same before and after connecting
Step 2: To find
The value of
Step 3: Formula used
where is current, is voltage and is resistance.
Step 4: Finding the current through resistor, before and after connecting
Current in the circuit before connecting ,
Current in the circuit after connecting ,
Step 5: Finding the value of
We know in a parallel combination, the potential difference is same in each branch.
Therefore, voltage through the resistor is equal to the voltage through
The value of is .
Hence, option B is correct.