Question

: What happens if the galvanometer and cell are interchanged at the balance point of the bridge?

Answer 1

A galvanometer is a device that detects or measures the magnitude of a tiny electric current. The movement of a magnetic needle or a coil in a magnetic field, which is an integral part of a galvanometer, is commonly used to indicate the current and its strength.

Complete answer:
If the galvanometer and cell are interchanged at the balance point of the bridge The balance point remains unaltered if the galvanometer and the cell are swapped. As a result, the galvanometer will display no current and the deflection will be zero.

Additional Information:
The D'Arsonval galvanometer is the most common, with an indicating system consisting of a light wire coil strung from a metallic ribbon between the poles of a permanent magnet. A torque, or twisting force, is produced when the magnetic field produced by a current travelling through the coil reacts with the magnetic field of the permanent magnet.

The coil, to which an indicator needle or mirror is attached, spins under the torque's action; the angle at which it rotates to balance the suspension's torsion provides a measure of the current flowing in the coil. The deflection of a beam of light reflected from the mirror or the movement of the needle are used to calculate the angle.

Note: The indicating needle (or mirror) of a ballistic galvanometer is designed to deflect in a proportional manner to the total charge travelling through its moving coil or to a short-duration voltage pulse. A ballistic galvanometer can be made out of any normal galvanometer, however the latter has less torque and more inertia in the coil.