17. 18. In the circuit shown swith S is connected to position 2 for a long time and then joined to position 1. The total heat produced in resistance R is: R www L 0000000 m S LE (a) 2R 2 HH www E R LE LE (b) (c) 2R 2R,R LE (R +R) (d) 2RR A solid cylinder attached to horizontal massless spring can roll without slipping along horizontal surface. Find time period of oscillation. M (a) 2 2k M.R K www (b) 3M 2k 2M (c) . 3k 3M (d) 2 2k 19. Assuming the sun to be a spherical body (e = 1) of radius R at a temperature of T K, evaluate the total radiant power, incident on Earth having radius ro, at a distance r from the Sun, where ro is the radius of the earth and is Stefan's constant. (a) 20. rROT (b) 4r ROT (c) (d) r The minimum and maximum distance of a satellite from the centre of the earth are 2R and 4R, respectively, where R is the radius of earth and M is the mass of earth. The radius of curvature at the point of maximum distance is 8R (a) 3 4R (b) 3 3R (c) 8 3R (d)