An electrical circuit is shown in figure. Calculate the potential difference across the resistor of `400 Omega` as will be measured by the voltmeter Vof resistance `400 Omega` either by applying Kirchhoff's rules or otherwise.

Answer

B, C

Explanation

Net resistance of voltmeter `(R=400 Omega)` and `400 Omega` will be `200 Omega`. Now, we are getting a balanced Wheatstone bridge with `100 Omega` and `200 Omega` resistors onn each side. Potential difference across each side will be `10 V` which will distribute in direct ratio of resistors `100 Omega` and `200 Omega`.
`:. V_(100Omega)/V_(200Omega)=100/200=1/2`
`or V_(200Omega)=(2/3)(10)=20/3V`