Amazing facts related to Science
Amazing Facts Related to Science-Some facts Which you Never Know-World Facts-Some Interview related Questions and their Answers
Q. Why the glass bottle can be unscrewed easily on warming?
Answer: When we warm the neck of a bottle whose lid is screwed tightly, the lid expands to be unscrewed easily.
Q. Why do clothes dry faster on hot day than a cool day?
Answer: On a hot day temperature of the surrounding and the liquid is more than on a cool day, hence the rate of evaporation is increased. So the clothes dry faster.
Q. Why does one end of the bridge rest over the rollers?
Answer: One end of the bridge rest over the rollers to allow the expansion of bridge when the temperature rises during the summer and due to the frictional force.
Q. Why does a glass tumbler sometimes crack when hot water is suddenly poured into it?
Answer: Glass is a bad conductor of heat. When hot water is suddenly poured into it, the inner layer of glass expands while outer layer doesn't expand. This difference in expansion causes the cracking.
Q. Why does a spoon kept in hot water become hot?
Answer: A spoon kept in hot water become hot because if the conduction of heat from hot water to spoon.
Q. Fireman wear helmets made of brass polished from outside. Why?
Answer: Fireman wear helmets made of brass polished from outside because brass polished helmets reflect most of the heat radiations and absorb very little while extinguishing fire.
Q. Why does ink leak out of a partially filled pen when taken to a higher altitude?
Answer: The density as well as pressure of air goes on decreasing with altitude, when a partially filled pen is taken to a higher altitude, it leaks because the pressure of air acting on the inside the pen is greater than the pressure of air outside.
Q. Why is light everywhere when the sun rises?
Answer: The light rays emitted by the sun come through the earth's atmosphere and are scattered off in all the directions when they are reflected by the molecules of the air and dust particles, that is why we get light everywhere when the sun rises.
Q. Why does a man sitting under a feel cooler?
Answer: A man sitting under the fan feels cooler due to evaporation of sweat from his body. Fan circulates the air and increases the evaporation of sweat. Evaporation has cooling effect.
Q. What is heart beat? Does heart beat faster after exercise? Why?
Answer: The heart pumps out blood to arteries above 70 times per minutes and this periodic contraction and expansion is called heart beat. The heartbeat can be counted by counting the pulse. The rate of heartbeat increases after doing any sort of physical exercise. It is due to an increase in the requirement of energy, it increases the rate of oxygen flow in the body.
Q. Why are the stars visible only at night?
Answer: Stars are present both at day and night but they are not visible in day because of the bright light of Sun so they are visible only at night.
Q. What is the reason of a small gap between the rails on a railway track?
Answer: A small gap is provided between the rails on a railway track to allow for expansion of rails when the temperature rises during the summer.
Q. What is the boiling point of a liquid?
Answer: Boiling point of a liquid is the temperature at which a liquid starts boiling and changes from liquid to gaseous state without undergoing any change in the temperature.
Q. Why does a bicycle tube has more punctures in summer than in winter?
Answer: A bicycle tube has more punctures in summer than in winter because in summer air filled inside the tube expand due to high temperature of the atmosphere.
Q. In what form LPG present in cylinder?
Answer: LPG present in liquid form in cylinder, when pressure is released, it evaporates and is obtained in gaseous form.
Q. Why does sugar dissolve faster in Hot milk than in cold milk?
Answer: In hot milk convectional currents are setup that is the hotmilk being lighter rises up and is replaced by cold milk, due to this sugar dissolves faster in hot milk than in cold milk.
Q. Why do we feel weak and tired when hungry?
Answer: When hungry we need energy as we have spent a lot of energy in different activities or work that's why we feel weak and tired after taking food we feel energetic refresh again because food give us energy to work.
Q. Why do we hear more clearly in a curtained room than in a room without curtains?
Answer: Curtained room reduce the reflection of sound and people hears only voice of the source and is not disturbed by reflections.
Q. If you want to hear a train approaching from far away why is it more convenient to put the ears to the track?
Answer: It is convenient to put the ears to the track because the reason is that the track is made up of iron and the velocity of sound is very high in iron than in air.
Q. How does a thermos flask help to keep a warm liquid warm and a cold liquid cold?
Answer: The construction of thermos flask is such that it avoids loss or gain of heat by conduction, Convection as well as by radiation. As there is neither loss nor gain of heat it keep a warm liquid warm and cold liquid cold.
Q. Why the glass bottle can be unscrewed easily on warming?
Answer: When we warm the neck of a bottle whose lid is screwed tightly, the lid expand to be unscrewed easily.
Q.Why do we get goosebumps?
Answer: There is a hormone called Adrenaline which is often released when we feel cold or if we are under stress and feel strong emotions such as anger,fear or excitement. It contracts the muscle called arrector pilli in the skin that is attached to the hair folicles hence pulling the hairs into upright position causing goosebumps.
Q. Why judges break the nib of their pen after passing a death sentence?
Answer: Breaking the nib is a symbolic act. It is done so that the pen which signed the person's life away will never be used to do that ever again.
Q. Why wedding finger goes on the left ring finger?
Answer: The wedding finger goes on the left ring finger because it's the only finger with a vein that connects to the heart.