পদার্থবিজ্ঞান প্রশ্ন

In the fourth arm S of a post office box has a wire of length of 1 m and cross-sectional area of 1×10-6 m² is connected Now, the galvanometer gives zero deflection when 10Ω plug from arm Q, 1000Ω plug from arm P and 2025Ω plug from arm R are removed from the box. Determine the specific resistance.