Q. Shown in the figure adjacent is a meter-bridge set up with null deflection in the galvanometer. The value of the unknown resistor R is
A) 13.75$\ \Omega$
B) 220$\ \Omega$
C) 110$\ \Omega$
D) 55$\ \Omega$
Explanation
(b) From balanced Wheatstone bridge concept,
$\ \ \ \frac{550\Omega}{R} = \frac{20}{80}$
$\Longrightarrow \ \ \ \ R = 220\Omega$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.