Q49. An ordinary clock loses time in summer. This is because (a) The length of the pendulum increases and time period increases (b) The length of the pendulum increases and time period decreases (c) The length of the pendulum decreases and time period increases (d) The length of the pendulum decreases and time period decreases …
Q1. When light enters a closed room through a small hole in the door, the image of an outside building appears as inverted on the opposite wall. This is because (a) The hole acts as a convex lens (b) Light takes curvature at the edges of the hole (c) Of rectilinear propagation of light (d) …
Q1. One litre of cold air weighs heavier than the dry air (1 Lit) because of the (a) Increased number of collisions between the molecules (b) Increased number of molecules at low temperature (c) Greater energy of molecules at high temperature (d) Lower energy of molecules at high temperature Answer: (b) Increased number of molecules …
Q1. The two branches of a plant give two different fruits : tomatoes and brinjals. This can be explained (a) By hybridisation (b) By grafting one with the other (c) By nature’s freak (d) By (a) or (c) mentioned above (UPSC Prelims 1979) Answer: (b) By grafting one with the other Explanation: Grafting is a …
Q1. Permanent hardness of water cannot be removed by (a) Boiling (b) Adding caustic soda (c) Distillation (d) Adding soda Answer: (a) Boiling Explanation: Permanent hardness is caused by dissolved salts of calcium and magnesium, such as chlorides and sulphates, which do not precipitate on boiling. Unlike temporary hardness, which can be removed by heating, …
Q1. A body partially floats in wafer when (a) The volume of the displaced liquid is equal to the volume of the body (b) The volume of the displaced liquid is greater than the volume of the body (c) The weight of the displaced water is equal to the weight of the body (d) The …
Q1. Less dew is formed on cloudy nights because (a) Clouds absorb the falling dew (b) Clouds scatter moisture (c) In cloudy nights the radiation takes place very slowly (d) In cloudy nights the radiation takes place very quickly (UPSC Prelims 1979) Answer: (c) In cloudy nights the radiation takes place very slowly Explanation: On …
Q1. In India it is found recently that incidence of Malaria is increasing because (a) The mosquitoes have become DDT resistant (b) Of poverty in villages (c) Of poor sanitary conditions (d) On account of increase in population it has become impossible to maintain cleanliness everywhere (UPSC Prelims 1979) Answer: (a) The mosquitoes have become …
Q1. After hatching by the hen, the young chicks come out of eggs within (a) One week (b) Two weeks (c) Three weeks (d) Four weeks (UPSC Prelims 1979) Answer: (c) Three weeks Explanation: The incubation period for hen eggs is typically around 21 days, or three weeks, during which the embryo develops inside the …