Question

how to take least countof voltmeter reading and ammeter reading ​

Answer 1

Least counting of voltmeter = Range of voltmeter / Total Division

For Example :- The voltmeter range is 0.5 - 0

No. of Division is 20

Therefore, least counting = 0.5 / 20 = 0.25 V

Answer 2

1. Connect Ammeter in series and voltmeter in parallel in an electrical circuit. Then Note down the readings in ammeter and voltmeter.
2.Least count is the smallest value that can be measured by the measuring instrument
Least count Formula:= value measured in n divisions/n
Least count of ammeter:
The smallest value of current that can be measured
For example:Let us calculate Least count of ammeter- 0-300mA
Least count=range of ammeter divided by number of division
Refer attachment 1:for ammeter picture
Small divisions=30
suppose there are 30 division then, least count is
=300/30=10mA
Least count of Voltmeter:
For example let us calculate  least count of Voltmeter 0-15volts.
Please refer to Attachment2 for voltmeter picture
Main division 15
sundivision 30
least count=15/30
=1/2=0.5
Least count  of this voltmeter is 0.5