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Question
In a meter bridge, the balance point is found to be at 39.5 cm from the end A when the resistor R is 12.5 Ω (right gap).
a) Determine the resistance of X (left gap).
b) Determine the balance point of the bridge if X and R are interchanged?
c) What happens if the galvanometer and cell are interchanged at the balance point of the bridge?
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Solution
Given:
lX = 39.5 cm, R = 12.5 Ω,
lR = (100 - lX) = 100 - 39.5 = 60.5 cm.
- Since, the bridge is balanced,
`"X"/"R" = "l"_"x"/"l"_"R"`
∴ X = `"l"_"x"/"l"_"R" xx "R"`
= `39.5/60.5 xx 12.5 = 8.16` Ω - When X and R are interchanged then their respective lengths also get interchange.
∴ The new balance point will be at 60.5 cm - If the galvanometer and the cell are interchanged then the balance point remains unchanged.
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