Question

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?

Answer 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 can be find by doing experiments.

thank you

Answer 2

Least count: the smallest reading which can be precisely measured with a  screw gauge, Vernier caliper, or any equipment is described at least count.

Least can be estimated by applying the formula,

for Ammeter,

least count of Ammeter = Range/number of divisions

Range = 0.4 - 0.2

            = 0.2A

Number of divisions = 10

so, least count of Ammeter = 0.2/10 = 0.02

here, main scale = 0.2A , n = 5 and least count = 0.02

reading of Ammeter = main scale + n × least count of Ammeter

= 0.2 + 5 × 0.02

= 0.2 + 0.1

= 0.3A

for voltmeter,

range = 2 - 1

           = 1V

number of divisions = 10

so, least count of voltmeter = 1/10 = 0.1

here, main scale = 2V, n = 1 and

least count of voltmeter = 0.1

reading of voltmeter = main scale + n × least count of the voltmeter

= 2 + 1 × 0.1 = 2.1V