Question

Four conductors of resistance 4, 3, 9 and 6 ohm are connected in AB,BC, CD and DA arms of a Wheatstone bridge. The bridge can be balanced by connecting.

• A. 1) 6 ohm in series with 3 ohm conductor
• B. 2) 4 ohm in parallel with 6 ohm conductor
• C. 3) 3 ohm in series with 3 ohm conductor
• D. 4) 5 ohm in series with 6 ohm conductor

Answer 1

The correct option is C 3) 3 ohm in series with 3 ohm conductor

To make it a wheatstone bridge $\frac{R_{AB}}{R_{AD}}=\frac{R_{BC}}{R_{CD}}$

Verification of options.

A) $\Rightarrow R_{BC}=9\Omega$

$\Rightarrow \frac{2}{3}\ne 1$

B) $\Rightarrow R_{AD}=\frac{6\times 4}{10}=2-4$

$\Rightarrow \frac{1}{0.6}\ne 1/3$

C) $\Rightarrow R_{BC}=6$

$\Rightarrow \frac{2}{3}=\frac{2}{3}$

$=$ 2/3

$\therefore$ Option C is correct