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

 

l.png

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

finding-least-count-of-ammeter-and-volmeter---example-2---teachoo.jpg

 

 

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

 

find-least-count-of-ammeter-and-voltmeter-example-3---teachoo.jpg

 

Ammeter Voltmeter

For Ammeter, 

We see that

10 Divisions is equal to 0.2 Amperes

 


So, 

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

  1. Class 10
  2. Chapter 12 Class 10 - Electricity (Term 2)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo