Time left 1 Stars twinkle because the intensity of light emitted by them changes with time the distance of the stars from the earth changes with time the refractive index of the different layers of the earth's atmosphere changes continuously, consequently the position of the image of a start changes with time the light from the star is scattered by the dust particles and air molecules in the earth's atmosphere 2 It takes much longer to cook food in the hills than in the plains, because in the hills the atmospheric pressure is lower than that in the plains and therefore water boils at a temperature lower than 100oC causing an increase in cooking time due to low atmospheric pressure on the hills, the water boils at a temperature higher than 100oC and therefore water takes longer to boil in the hills the atmospheric density is low and therefore a lot of heat is lost to the atmosphere in the hills the humidity is high and therefore a lot of heat is absorbed by the atmosphere leaving very little heat for cooking 3 Moment of inertia is vector scalar phasor tensor 4 Of the following natural phenomena, tell which one known in Sanskrit as 'deer's thirst'? Rainbow Earthshine Halo Mirage 5 Light travels at the fastest speed in glass water hydrogen vacuum 6 Railway tracks are banked on curves necessary centrifugal force may be obtained from the horizontal component weight of the train to avoid frictional force between the tracks and wheels necessary centripetal force may be obtained from the horizontal component of the weight of the train the train may not fly off in the opposite direction 7 On a cold day when a room temperature is 15oC, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15oC, because metals have higher thermal capacity than plastics plastics have a lower density than metals metals are good conductor of heat plastics have a higher thermal conductivity than metals 8 Sound produced at a point is heard by a person after 5 second, while the same sound is heard by another person after 6 seconds. If the speed of sound is 300 m/s, what could be the maximum and minimum distances between the two persons? 1.8 km, 0.15 km 2.2 km, 0.20 km 2.8 km, 0.25 km 3.3 km, 0.30 km