Question

in ohm law experiment a student observed that the pointer of voltmeter coinside with 15 division find the reading of the voltmeter last count 0.05volt​

Answer 1

Least count of any device of measurement is the least reading it can take or measured by the device.

Thus, LC = Value in n divisions/ n

In this case LC = 0.05v and the pointer (n) is at 15th division.

Therefore, the observed reading of the voltmeter = 0.05 X 15 = 0.75 volts.