NCERT Exercise 3.10 - Current Electricity
Question: (a) In a metre bridge, 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 metre 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?
Answer: (a) **X = 8.2 Ω**; thick copper strips minimise contact resistance. (b) Balance point = **60.5 cm** from A. (c) **No current** through galvanometer — balance is undisturbed.
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