11. An incompressible liquid is kept in a container having a weightless piston with a hole. A capillary tube of inner radius 0.1 mm is dipped vertically into the liquid through the airtight piston hole, as shown in the figure. The air in the container is isothermally compressed from its original volume V to 100 101 Vo with the movable piston. Considering air as an ideal gas, the height (h) of the liquid column in the capillary above the liquid level in cm is [Given: Surface tension of the liquid is 0.075 N m, atmospheric pressure is 105 N m, acceleration due to gravity (g) is 10 m s, density of the liquid is 103 kg m and contact angle of capillary surface with the liquid is zero] air liquid wwwwww Piston 19 g 12. In a radioactive decay process, the activity is defined as A=- dN dt where N(t) is the number of radioactive nuclei at time (t). Two radioactive sources, S, and S2 have same activity at time t = 0. At a later time, the activities of S, and S2 are A, and A2, respectively. When S, and S have just completed their 3rd and 7th half-lives, respectively, the ratio A A2 is 13. One mole of an ideal gas undergoes two different cyclic processes I and II, as shown in the P-V diagrams below. In cycle I, processes a, b, c and d are isobaric, isothermal, isobaric and isochoric, respectively. In cycle II, processes a, b, c and d are isothermal, isochoric, isobaric and isochoric, respectively. The total work done during cycle I is W and that during cycle II is Wil. The ratio W/W is (II) (I) P (Pa) P (Pa) 4Po 4Po b 2Po b' 2Po Po V (m) V (m) Vo 2V0 Vo 2Vo 4V0