Three voltmeters, all having different internal resistances are joined as shown in figure. When some potential difference is applied across A and B, their readings are $V_1$, $V_2$ and $V_3$.
Choose the correct option.
Applying Kirchhoff’s Voltage Law (KVL) across the loop: \(V_1 + V_2 - V_3 = 0 \implies V_1 + V_2 = V_3.\)
The Correct answer is: $V_1 + V_2 = V_3$
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: