Q26 of 27 Page 1

The current flowing through a resistor connected in an electrical circuit and the potential difference developed across its ends are shown in the given ammeter and voltmeter. Find the least count of the voltmeter and ammeter .What is the voltage and the current across the given resistor?

The Least count of any measuring instrument is defined as the minimum precise value which can be measured using that instrument. The formula for the least count of the measuring instrument is as follows:


Now the for the ammeter,


Range = 0V - 1V = 1V


Total Number of divisions = 50



Similarly, for the voltmeter,


Range = 3V


Number of Divisions = 30


Hence,



= 0.1 V


Now for finding the current through the resistor,


Current = Least Count × Ammeter division


= 15 × 0.02


= 0.3 A


Voltage across the resistor is given by, Voltage = 21 × 0.1


= 2.1 V


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