- HOW CAN WE FIND ZERO ERROR AND LEAST COUNT OF VOLTMETER AND AMMETER?
First inspect the voltmeter/ammeter indicator hand with no connection to it. If the indicator hand is in the zero position then the zero error is 0. If it is it is showing 1 division then the zero error is 1 division and it should be added to the voltage/ current measurement after connecting to circuit.
Above case is called +ve zero error
If the indicator hand is found beyond the 0 mark in off state of the meter, then the zero error is called negative zero error and the no. of divisions must be subtracted from the final reading
Least count is the lowest possible measurement possible by a device. If suppose a voltmeter has marks such that 10 small divisions make 1 volt then the least count will be 1/10 th of a volt. if 10 small divisions are shown 10 volt then the least count will be 1 volt
Similarly same follows for ammeter