Current Electricity

Two resistances R1=XΩ and R2=1Ω are connected to a wire AB of uniform resistivity, as shown in the figure. The radius of the wire varies linearly along its axis from 0.2‌mm at A to 1‌mm at B. A galvanometer (G) connected to the center of the wire, 50‌cm from each end along its axis, shows zero deflection when A and B are connected to a battery. The value of X is