In the adjoining circuit, the e.m.f. of the cell is 2 volt and the internal resistance is negligible. The resistance of the voltmeter is `80 ohm`. The reading of the voltmeter will be

Options

A. 0.80 volt
B. 1.60 volt
C. 1.33 volt
D. 2.00 volt

Answer

C

Explanation

(c ) Total resistanceof the circuit `= (80)/(2) + 20 = 60 Omega`
`implies` Main current `i= (2)/(60) = (1)/(30) A`
Combination of voltmeter and `80 Omega` resistance is connected in series with `20 Omega`, so current through `20 Omega`
and this combination will be same `= (1)/(30) A`
Since the resistance of voltmeter is also `80 Omega`, so this current is equally distributed in `80 Omega` , so this current is equally distributed in `80 Omega` resistance and voltmeter (i.e., `(1)/(60) A` through each)
`P.D.` across `80 Omega` resistance `= (1)/(60) xx 80 = 1.33 V`