JEE Main2004PhysicsCurrent ElectricityActual
In a metre bridge experiment null point is obtained at 20 ~cm from one end of the wire when resistance X is balanced against another resistance Y . If X < Y , then where will be the new position of the null point from the same end, if one decides to balance a resistance of 4 X against Y?
Options
- A50 ~cm
- B80 ~cm
- C40 ~cm
- D70 ~cm
Correct answer
A. 50 ~cm
Step-by-step solution
We have from meter bridge experiment, R ₁ R ₂ = ₁ ₂ , where ₂= (100- ₁ ) cm In the first case, X / Y=20 / 80 In the second case 4 X Y = 100- =50 ~cm .