Question

In a meter bridge, when galvanometer and cell positions are interchanged, ______.

Options

• Exactly same relation between four resistance is obtained

• Inverse relation between four resistance is obtained

• No relation is obtained between four resistances

• Can’t predict the relation

Answer 1

In a meter bridge, when galvanometer and cell positions are interchanged, exactly same relation between four resistance is obtained.

Explanation:

The galvanometer is linked between B and D in the circuit (1) depicted, while the battery is connected between A and C. `"P"/"R" = "Q"/"S"` in the bridge balanced condition.

(1)	(2)	(3)

When the battery and the galvanometer are interchanged, the circuit takes the form (2). The circuit (2) can be redrawn as circuit (3). The ratio of the resistances in the bridge balanced condition is `"P"/"R" = "Q"/"S"` which is same as, `"P"/"R" = "Q"/"S"`.