Polytechnic Hub

Ohmmeter

Types of Ohmmeter :

Construction of Ohmmeter :

It consist of 2 coils, coil ‘C’ and coil ‘P’ fixed right angles with one another. When current flows through these two coils, both the coils, exert force on the magnetic needle. The direction of these two forces are exactly opposite, to each other. Coil ‘P ‘ exert the force on the magnetic needle and tries to move the needle such  that it align along the axis of coil ‘P’. While the force exerted by the coil ‘C’ on the magnetic needle makes it alying along the axis of coil ‘C’. Pointer is attached to the magnetic needle, the scale of this meter starts with ‘∞’and ends at ‘0’.It is scale calibrated in kΩ .