In the following circuit if deflection in the galvanometer is zero then the value of resistance (R) will be :

CONCEPT:

Wheatstone bridge: It is an electrical circuit used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, one leg of which includes the unknown component.

The condition for zero deflection in the galvanometer is given by the following formula:

Formula :

\(\frac{{{R_a}}}{{{R_b}}} = \frac{{{R_1}}}{{{R_2}}}\)

where R_a = R_b = R₁ = R₂ = Resistors connected

CALCULATIONS:

Given that,

 Ra = 2 ,Rb = 3 ,R1 = 4 ,R₂ = X

From the above formula,

\(\frac{{{R_a}}}{{{R_b}}} = \frac{{{R_1}}}{{{R_2}}}\)

putting all the values ,

2/3 = 4/X = 6Ω 

The correct option is 6Ω 

Additional Information

Galvanometer:

• The electromechanical instrument used for detecting and indicating an electric current called Galvanometer.
• A galvanometer works as an actuator, by producing a rotary deflection, in response to electric current flowing through a coil in a constant magnetic field.