Question

Calculate $I$ for the given circuit diagram.

• A. 10 A
• B. 5 A
• C. 2.5 A
• D. 20 A

Answer 1

Answer: (A)

It is a balanced Wheatstone bridge.
Hence no current flows through resistance of arm $BD$ and the resistance of arm $BD$ is ineffective.
$\therefore \frac{R_{AB}}{R_{BC}}=\frac{R_{AD}}{R_{DC}}<br/>\Rightarrow \frac{5\Omega }{5\Omega }=\frac{5\Omega }{5\Omega }$
Resistance of arm $ABC=5\Omega +5\Omega =10\Omega$ Resistance of arm $ADC=5\Omega +5\Omega =10\Omega$ The effective resistance between $A$ and $C$ is