Question

The current in a conductor and the potential difference across its ends are measured by an ammeter and a voltmeter. The meters draw negligible currents. The ammeter is accurate but the voltmeter has a zero error (that is, it does not read zero when no potential difference is applied). Calculate the zero error if the readings for two different conditions are 1.75 A, 14.4 V and 2.75 A, 22.4 V.

Answer 1

The Zero Error will be V = 0.4 V

Explanation:

Step 1:

Considering voltmeter reading when, the voltage is 0 be X

We know V = IR

$\frac{l_{1} R}{l_{2} R}=\frac{V_{1}}{V_{2}}$

$\frac{1.75}{2.75}=\frac{14.4-V}{22.4-V}$

$\frac{7}{11}=\frac{14.4-V}{22.4-V}$

$7 \times(22.4-V)=11(14.4-V)$

$156.8-7 V=158.4-11 V$

$V=0.4 V$

Where we understood that the variables are represented as below

V = Voltage drop across the circuit

R = Resistance of the circuit (which Opposes the flow of current)

I = Current flowing in the circuit.