JEE Main2018PhysicsCurrent ElectricityActual
In a circuit for finding the resistance of a galvanometer by half deflection method, a 6   V battery and a high resistance of 11   kΩ are used. The figure of merit of the galvanometer is 60   μA   division - 1 . In the absence of shunt resistance, the galvanometer produces a deflection of θ = 9 divisions when current flows in the circuit. The value of the shunt resistance that can c
Options
- A550 Ω
- B220 Ω
- C55 Ω
- D110 Ω
Correct answer
D. 110 Ω
Step-by-step solution
We are given a galvanometer connected in the first circuit in the above figure, where E = 6   V , R   =   11   kΩ and the deflection θ   =   9 divisions. The galvanometer has a resistance of G . The current in the circuit, I = E R + G     . . . ( 1 ) Also, since the figure of merit is 60   μA / division I   =   60 × 9   μA   =   540   μA     . . . ( 2 ) Substituting equation ( 2 ) in ( 1 ) , 540 ×