49. Light incident normally on a plane mirror attached to a galvanometer coil retraces backwards as shown in figure. A current in the coil produces a deflection of 3.5 of the mirror. What is the displacement of reflected spot of light on a screen placed 1.5 m away? d 1.5 m (1) 10.5 cm (2) 18.31 cm (3) 15 cm (4) 3 cm 50. Two plane mirrors are lying perpendicular to each other, there is lamp in between mirrors. Then number of images of lamp will be (1) 3 (2) 4 (3) 5 (4) 6 51. The enthalpy of vaporisation of water at 100C is 40.63 KJ mol. The value AE for this process would be :- (1) 37.53 KJ mol (2) 39.08 KJ mol (3) 42.19 KJ mol (4) 43.73 KJ mol 52. For which of the following AG is (-) ve? (1) HO(l) (2) H2O(s) 236 K 1 atm 283 K 1 atm (3) HO () 290 K (4) H2O (s) 1 atm 0C 1 atm H2O(g) H2O(l) H2O(s) H2O(l)