Question

Find the value of series of combination of resistance R and X in $\Omega$

• A. 14 $\Omega$
• B. 26 $\Omega$
• C. $\frac{84}{13}\Omega$
• D. None of these

Answer 1

The correct option is B 26 $\Omega$

For potentiometer the voltage source is providing constant current in the circuit and if $R$ and $X$ are connected in series it will form Wheatstone's network so the balancing condition is

$\frac{X}{R}=\frac{70}{60}$

$X=\frac{7\times 12}{6}=14\Omega$

equivalent resistance of $R$ and $X$ in series$=R+X=26ohms$.Hence, correct answer is option B.