NEETPhysicsCurrent Electricity
A meter bridge is set up with a resistance R₁ in the left gap and a resistance R₂ in the right gap. The balance point is obtained at a distance l from the left end. Match the modifications made to the circuit in List-I with their corresponding effects on the balance point in List-II. List-I List-II (A) Connecting a resistor in series with R₁ (I) Shifts towards the left end (B) Connecting a resistor in parallel with R
Options
- A(A)-(I), (B)-(II), (C)-(III), (D)-(IV)
- B(A)-(II), (B)-(I), (C)-(IV), (D)-(III)
- C(A)-(II), (B)-(I), (C)-(III), (D)-(IV)
- D(A)-(I), (B)-(II), (C)-(IV), (D)-(III)
Correct answer
C. (A)-(II), (B)-(I), (C)-(III), (D)-(IV)
Step-by-step solution
The balance condition for a meter bridge is R₁ R₂ = l 100 - l . (A) Connecting a resistor in series with R₁ increases the effective resistance in the left gap. To maintain the ratio, the balancing length l must increase, so the balance point shifts towards the right end. Hence, (A) matches with (II). (B) Connecting a resistor in parallel with R₁ decreases the effective resistance in the left gap. The balancing length l must decrease, so the balance point shifts towards the left end. Hence, (B) matches with (I). (C)