In the given circuit, batteries are ideal and Galvanometer shows zero deflection, then the value of 'R' is:
The Wheatstone bridge is balanced when \(R_3 = 144 \, \Omega\). If \(R_2\) and \(R_1\) are interchanged, the bridge balances for \(R_3 = 169 \, \Omega\). The value of \(R_4\) is: