Question

To what value must R3 be adjusted to balance a Wheatstone bridge it the unknown resistance Rx is 155 Ohm. R1 is 46.5 Ohm, and R2 is 185 Ohm? The bridge is said to be balanced when the current through the galvanometer (G) is zero. Number ________ Ohm

Answer 1

for a wheatstone bridge to be balanced , we have the condition as :

$\frac{R_{1}}{R_{3}} =\frac{R_{2}}{R_{x}}$

R_x = 155 ohm   , R₁ = 46.5 ohm   , R₂ = 185 ohm , R₃ = ?

$\frac{46.5}{R_{3}} =\frac{185}{155}$

R₃ = 155* 46.5 / 185

R₃ = 38.96 ohm