Question

Two resistances $500\Omega$ and $1000\Omega$ are connected in series with a battery of $1.5V$. The voltage across the $1000\Omega$ resistance is measured by a voltmeter having a resistance of $1000\Omega$. The reading in the voltmeter would be _____.

• A. $1.5V$
• B. $1V$
• C. $0.75V$
• D. $0.5V$

Answer 1

The correct option is C $0.75V$

The current will distribute among 1000$\Omega$ resistor and 1000$\Omega$ voltmeter eqaully because of equal resistors.

$I=2I_1{I}_1=\frac{I}{2}\to \left(1\right)$

Now 1000$\Omega$ resistors are in parallel so equivalent circuit Fig(2)

Total $I=\frac{V}{Req}I=\frac{1.5}{1000}AQ{I}_1=\frac{I}{2}=\frac{1.5}{2000}A$

Reading of voltmeter$=I_1\times 1000\Omega =\frac{1.5}{2000}\times 1000=\frac{3}{4}=0.75V$