The smallest value that can be measured is called Least Count .
In Ammeter and Voltmeter, the smallest value that can be measured will be least count.
Let's do this by some examples
Find Least count of Ammeter and Voltmeter given below
Here,
Voltmeter | Ammeter |
For Voltmeter, We see that 5 Division is equal to 2 Volts
So, Least Count = 2/5 = 0.4 V |
For Ammeter, We see that 5 Division is equal to 10 Amperes
So, Least Count = 10/5 = 2 A |
So, Least Count of Voltmeter is 0.4 V and Least count for Ammeter is 2A
Find Least count of Ammeter and Voltmeter given below
Voltmeter | Ammeter |
For Voltmeter, We see that 10 Divisions is equal to 5 Volts
So, Least Count = 5/10 = 0.5 V |
For Ammeter, We see that 10 Divisions is equal to 100 Milli Amperes
So, Least Count = 100/10 mA = 10 mA = 10 × 10 ^{ -3 } A = 10 ^{ -2 } A = 0.01 A |
So, Least Count of Voltmeter is 0.5 V and Least count for Ammeter is 0.01 A
Find Least count of Ammeter and Voltmeter given below
Ammeter | Voltmeter |
For Ammeter, We see that 10 Divisions is equal to 0.2 Amperes
Least Count = 0.2/10 = 0.02 A |
For Voltmeter, We see that 10 Division is equal to 1 Volt
So, Least Count = 1/10 = 0.1 V |
So, Least Count of Voltmeter is 0.4 V and Least count for Ammeter is 0.02 A
An ammeter has a range of 0-3 ampere and there are 30 divisions on its scales. What is its least count?
This means that
In Ammeter
30 Division is 3 A
So,
Least Count = 3/30
= 1/10
= 0.1 A
So, Least Count of Ammeter is 0.1 A