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 …
Q1. Stripes on the back of the animals are the indication of (a) Mating habit (b) Food habit (c) Cave dwelling (d) Matching of skin colour with surroundings (UPSC Prelims, 1979) Answer: (d) Matching of skin colour with surroundings Explanation: Stripes and patterns on animals serve as camouflage, helping them blend with their environment. This …
Q1. Green plants in the sea are useful for the respiration of fish because (a) They give out oxygen (b) They give out carbon dioxide (c) The give out oxygen and carbon dioxide simultaneously (d) They take oxygen and give out carbon dioxide (UPSC Prelims, 1979) Answer: (a) They give out oxygen Explanation: Aquatic plants …
Q1. Higher plants take up Nitrogen as (a) Nitrites only (b) Nitrates only (c) Nitrates and ammonia (d) Urea (UPSC Prelims, 1979) Answer: (b) Nitrates only Explanation: Higher plants absorb nitrogen primarily in the form of nitrates, which are soluble and easily transported through the soil. Nitrates are converted into amino acids and proteins, essential …
Q1. The most common substance responsible for pollution is (a) Smoke (b) Carbon dioxide (c) Sulphur dioxide (d) Carbon monoxide (UPSC Prelims, 1979) Answer: (a) Smoke Explanation: Smoke, which contains a mixture of particulate matter and harmful gases, is a major contributor to air pollution. It originates from industrial emissions, vehicle exhausts, and burning of …
Q1. You are travelling in a car and a thunder storm suddenly takes place. What will be your first step ? (a) Stop the car, get out of it and lie flat in the field (b) Stand below a tree (c) Go to a nearby wood pole and stick to it (d) Lie flat in …