Two resistors of `500 Omega` and `300 Omega` are connected in series with a battery of emf `20 V.A` voltmeter of resistance `500 Omega` is used to measure the `p.d` across the `500 Omega` resistor. The error in the measurement is.

Options

A. 1.4 V
B. 2.4 V
C. 3.4 V
D. 4.4 V

Answer

C

Explanation

With ideal voltmeter

`V_1 = (500)/(500 + 300) xx 20 = 12.5 V`

`V'_1 = (250)/(250 + 300) xx 20 = 9.09 V`
Error in measurement
`V_1 - V'_1 = 12.5 - 9.09 = 3.4 V`.