JEE Advanced Model Paper 20 with solutions for online practice

A voltmeter of resistance R1 and an ammeter of resistance R2 are connected in series across a battery of negligible internal resistance (fig 1) when a resistance R is connected in parallel to voltmeter, the ammeter reading becomes thrice and voltmeter reading becomes one third. (fig 2). Then R2 = nR/3.Find the value of n.