Hydrogen is in abundance around the sun but not around earth. Why? ANSWER: The escape velocity on the sun is very high compared to that on the earth. The gravitational pull of the sun is very large because of its larger mass compared to that of the earth. So it is very difficult for hydrogen to escape from the sun's atmosphere because r.m.s velocity of hydrogen is more than escape velocity(11.2 km/sec). But on the sun r.m.s velocity of the hydrogen is less than the escape velocity of the sun. Hence hydrogen is abundant on sun. Note: r.m.s velocity means root mean square velocity) escape velocity of the planet/star is the minimum velocity required to a body to escape form the planet/star.
EVOLUTION QUESTIONS AND ANSWERS Question: In damped weather, automobile ignition failure happens. Give the reason? Answer: Generally, the spark plug's surface accumulates a film of dirt. The surface dirt hygroscopic hence attracts moisture from the air. Therefore, in humid weather, plugs become quasi-conductor. So ignition failure happens. Question: Why a charged body can attract a piece of paper? Answer: A piece of paper is a dielectric. When a positively charged body is brought near to piece of paper, atoms of paper get polarized (In the neutral body, charge separation as + and -) with the center of opposite charge of atoms coming closer to the charged body. So the charged body can attract a piece of paper. Question: A charged body can attract another uncharged body? Explain why? Answer: Yes, because when a charged body is brought very near to an uncharged body, an opposite induced charge will develop across the uncharged body. The therefore charged