In the given circuit the the internal resistance of the 18 V cell is negligible. If R1 = 400 $\Omega $, R3 = 100 $\Omega $ and R4 = 500 $\Omega $ and the reading of an ideal voltmeter across R4 is 5V, then the value of R2 will be :

Question

In the given circuit the the internal resistance of the 18 V cell is negligible. If R₁ = 400 $\Omega $, R₃ = 100 $\Omega $ and R₄ = 500 $\Omega $ and the reading of an ideal voltmeter across R₄ is 5V, then the value of R₂ will be :

300 $\Omega $