The current flowing through a resistor connected in a circuit and the potential difference developed across its ends are as shown in the diagram by milliammeter and voltmeter readings respectively:
(a) What are the least counts of these meters?
(b) What is the resistance of the resistor?

(a) Least count of ammeter = $10mA$  $(\because one\ marking\ or\ line\ denotes\ the\ value\ 10)$

    Least count of voltmeter = $0.1V$   $(\because one\ marking\ or\ line\ denotes\ the\ value\ 0.1)$

(b) Given:

Reading of ammeter, $I=200+(5\times 10)=200+50=250mA=\frac {250}{1000}A=0.25A$

Reading of voltmeter, $V=2+(4\times 0.1)=2+0.4=2.4V$

To find: Resistance of the resistor, $R$.


We know that, resistance is given as-

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

Putting the given values, we get-

$R=\frac {2.4}{0.25}$

$R=\frac {24\times 100}{25\times 10}$

$R=\frac {240}{25}$


Thus, the resistance of the resistor, $R$ is 9.6 Ohm.


Simply Easy Learning

Updated on: 10-Oct-2022


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