Question

Question 3.10: (a) In a metre bridge [Fig. 3.27], the balance point is found to be at 39.5 cm from the end A, when the resistor Y is of 12.5 Ω. Determine the resistance of X. Why are the connections between resistors in a Wheatstone or meter bridge made of thick copper strips? (b) Determine the balance point of the bridge above if X and Y are interchanged. (c) What happens if the galvanometer and cell are interchanged at the balance point of the bridge? Would the galvanometer show any current?

Class 12 - Physics - Current Electricity Current Electricity Page-128

Answer 1

(a) at balance,
$\frac{X}{Y}=\frac{l}{100-l}$
Given, Y = 12.5Ω ,l = 39.5 cm
so, (100 - l) = (100 -39.5) = 60.5 cm

now, X/12.5 = 39.5/60.5
X = 395 × 12.5/605 = 8.16Ω
The connection between resistors in a wheatstone bridge or metre bridge is made of thick copper strip because it provide negligible resistance by connecting wires.

(b) in question, it is given that the balance point is found to he at 39.5 cm from end A. now when X and Y are interchanged the balance point will be at 60.5 cm from end A.

(c) in balance condition of the bridge , the cell and the Galvanometer can be exchanged, the galvanometer will be show zero deflection.

Answer 2

Answer:

Explanation:

This is the best solution for this question