A constant `60 V` dc supply is connected across two resistors of resistance `400 k Omega` and `200 k Omega`. What is the reading of the voltmeter, also of resistance `200 k Omega`, when connected across the second resistor as shows in Fig. `6.48`?

Options

A. `12 V`
B. `15 V`
C. `20 V`
D. `30 V`

Answer

A

Explanation

Effective resistance across the voltmeter is `200//2 = k Omega`.
Total resistance across dc supply is `400 + 100 = 500 k Omega`.
Thus, the voltage across the voltmeter is `100//500(60 V) = 12 V`.