Question

In an experiment according to set up, when $E_{1}=12 \, V$ and internal resistance zero, $e=2 \, V$ . The galvanometer reads zero, then $X$ would be-

• A. $200$
• B. $500$
• C. $100$
• D. $10$

Answer 1

Answer: (C)

Voltage across $X$ is $2 v$
$\text { So }\left(\frac{E_1}{500+X}\right) X=2$
$\Rightarrow\left(\frac{12}{500+X}\right) X=2 $
$\Rightarrow 12 X=1000+2 X $
$\Rightarrow 10 X=1000$
$ X =100 \,\Omega$