(a) What is the least count of the voltmeter?(b) What is the reading shown by the voltmeter?(c) If this voltmeter is connected across a resistor of 20Ω
">

Consider the scale of a 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 this voltmeter is connected across a resistor of 20Ω


(a) Maximum value of voltmeter = 3.0 (given)

Total count of marking in the voltmeter= 20

Therefore, 

Least count of voltmeter = $\frac {3}{20}=0.15V$ 


(b) Reading shown by the voltmeter is-

$\Rightarrow 1.5+0.15+0.15$    $(\because each\ marking\ has\ the\ value\ 0.15)$

$\Rightarrow 1.8V$.


(c) Given:

Resistor, $R=20\Omega$

Reading of voltmeter, $V=1.8V$


To find: Current flowing through the resistor, $I$.


Solution:

By Ohm's law, we know that, 

$V=I\times R$

In terms of $I$ it is given as-

$I=\frac {V}{R}$

Putting the required values, we get-

$I=\frac {1.8}{20}$

$I=0.09A$

Thus, the current flowing through the resistor is 0.09A.

Tutorialspoint
Tutorialspoint

Simply Easy Learning

Updated on: 10-Oct-2022

352 Views

Kickstart Your Career

Get certified by completing the course

Get Started
Advertisements