AP EAMCET Medical 2016 Paper

Three resistors of resistances 100 Ω, 200 Ω and 400 Ω are connected in series with a cell of emf 7.8 V and negligible internal resistance. A voltmeter of resistance 200 Q connected across the two resistors 200 Ω and 400 Ω separately reads V1 and V2 respectively.Then V2−V1 is equal to