2. When the reading is zero, the levels in the two reservoirs are equal. Assume that fluid C is methane at atmospheric pressure and 20C, that liquid B in the reservoirs is kerosene (specific gravity = 0.8), and that liquid A in the U tube is water. The inside diameters of the reservoirs is 5.0 cm. In order to keep an upper-limiting percent error of 5% for a reading of R=30.0 mm of the two-liquid manometer as shown in Figure 1. What should the inside diameter of U-tube be? Pa Po Pc PB T R PA Figure 1 Differential (or Two-liquid) manometer