In the circuit shows in Fig. `6.42`, resistors `X` and `Y`, each with resistance `R`, are connected to a `6 V` battery of negligible internal resistance. A voltmetre, also of resistance `R`, is connected across `Y`.

What is the reading of the voltmeter?

Options

A. `zero`
B. `between 0 and `3 V``
C. `3 V`
D. `between `3 V` and `6 V` `

Answer

B

Explanation

The circuit may be redrawn as follows:

Current is given `I = (6)/((3)/(2) R) = (4)/(R ) A`
Therefore, current through the voltmeter is `I//2` or `2//R A`. Hence, the reading of the voltmeter is `(2//R)(R )` or `2 V`.