Which of the following actions will not increase the sensitivity of a moving coil galvanometer?
Answer Details
Using a light pointer will not increase the sensitivity of a moving coil galvanometer.
The sensitivity of a moving coil galvanometer depends on various factors, such as the strength of the magnetic field, the number of turns of the coil, the area of the coil, and the moment of inertia of the coil. A more sensitive galvanometer is one that can detect even a small current flowing through it and produce a large deflection.
Using a strong temporary magnet, increasing the area and number of turns of the coil, and using a weak hair spring are all actions that can increase the sensitivity of a moving coil galvanometer. A strong magnet will increase the magnetic field strength and thus increase the torque on the coil. Increasing the area and number of turns of the coil will increase the amount of current induced in the coil for a given magnetic field, and a weak hair spring will reduce the restoring torque and allow the coil to be more easily deflected.
However, using a light pointer will not affect the sensitivity of a moving coil galvanometer. A light pointer is simply used to reduce the moment of inertia of the coil, which makes it easier to deflect the coil for a given amount of torque. This does not directly affect the sensitivity of the galvanometer.