Question

Consider the circuit containing resistors and an ideal battery. Potential difference $V_a-V_b$ is equal to (where points 'a' and 'b' are as shown)

• A. -5V
• B. -10V
• C. -12.5V
• D. 5V

Answer 1

Answer: (B)

-10V

We get the equivalent resistance of all the resistors apart from

the $11\Omega$ as $5\Omega$. This $5\Omega$ and $11\Omega$ are in series.

Hence equivalent resistance is

$Req.=5\Omega +11\Omega =16\Omega$
Therefore current through circuit is

$I=\frac{32V}{16\Omega }=2A$

Applying KVL, we get

$V_a-11\times 2+32-V_b=0\Rightarrow V_a-V_b=-10V$