Question

Consider the sacle of voltmeter shown in the diagram and answer the following questions : 

(a) What is the least count of the voltmeter?

(b) What is the reading shown by the voltmeter ?

(c) If the voltmeter is connected across a resistor of 20 `Omega` how much current is flowing through the resistor?

Answer 1

(a) Least count = `3/20 = 0.15V`

(b) `(1.5 + 0.15 + 0.15)V = 1.8 V`

(c) R = 20 `Omega`

     `V = 1.8 V`

`therefore I = ?`

By ohm’s law 

`V = IR`

`1.8/20 = I                           therefore I = 0.09 A`