The Universe (Part-4)

Total Questions: 50

21. The Asteroids are small celestial bodies in the solar system which are found between the planets [U.P.P.C.S. (Pre) 2008]

Correct Answer: (b) Mars and Jupiter
Solution:The group of small pieces of rock revolving around the Sun between the orbits of Mars and Jupiter are called asteroids. Asteroids very in Size & Some could be of 1000 km diameter.

Asteroids, sometimes called minor planets, are the rocky remnants of material leftover from the formation of the solar system and its planets approximately 4.6 billion years ago.

They are small, rocky objects that orbit the Sun in highly flattened, or "elliptical" circles, often rotating erratically, tumbling, and falling through space. The majority of asteroids originate from the main asteroid belt, a region between the orbits of Mars and Jupiter. Asteroids are found in other places, too.

For example, some asteroids are found in the orbital path of planets. This means that the asteroid and the planet follow the same path around the sun. Earth and a few other planets have asteroids like this. Although asteroids orbit the Sun like planets, they are much smaller than planets.

Most asteroids are irregularly shaped, though a few are nearly spherical, and they are often pitted or cratered. Some asteroids are hundreds of miles in diameter, but many more are as small as pebbles.

More than 150 asteroids are known to have a small companion moon (some have two moons). There are also binary (double) asteroids, in which two rocky bodies of roughly equal size orbit each other, as well as triple asteroid systems.

22. What is the difference between asteroids and comets? [I.A.S. (Pre) 2011]

1. Asteroids are small rocky planetoids, while comets are formed of frozen gases held together by rocky and metallic material.

2. Asteroids are found mostly between the orbits of Jupiter and Mars, while comets are found mostly between Venus and Mercury.

3. Comets show a perceptible glowing tail, while asteroids do not.

Which of the statements given above is/are correct?

Correct Answer: (b) 1 and 3
Solution:Asteroids are generally considered to be made up of metals and rocky material, while Comets are made up of ice, dust and rocky material. Asteroids are found much closer to the Sun.

Comets are formed farther from the Sun in 'Kuiper Belt' and Oort cloud. Comets sprout tails when they approach towards the Sun. Asteroids typically remain much more solid and self-contained even when near the Sun.

23. The tail of comet is directed away from the Sun, because- [I.A.S. (Pre) 19]

Correct Answer: (c) The radiation emitted by the Sun exerts a pressure on the comet throwing its tail away from the Sun
Solution:In the outer solar system, comets remain frozen and are extremely difficult or impossible to detect from Earth due to their small size. As a comet approaches the inner solar system, solar radiation causes the volatile material within the comet to vaporize the steam out of the nucleus, carrying the dust away with them.

The steams of dust and gas thus released from a huge, extremely tenuous atmosphere around the comet called Coma and the Force exerted on the Coma by the sun's radiation pressure causes an enormous tail to form, which points away from the Sun. Hence (c) is the correct answer.

24. Hale-Bopp is the name of a- [M.P.P.C.S. (Pre) 1997]

Correct Answer: (a) Comet
Solution:Hale-Bopp is a long period comet that was discovered is 1995. It was shining near the orbit of Jupiter around 23 July, 1995. This comet was discovered by Alan Hale (New Mexico) and Thomas Bopp (Arizona) so it was named by Joining the last names of the two astronomers.

25. With which planet comet Shoemaker-Levy collided- [I.A.S. (Pre) 196]

Correct Answer: (c) Jupiter
Solution:Comet Shoemaker-Levy-9 was discovered on 24 March 1993 when astronomers Carolyn Shoemaker, Eugene M Shoemaker and David Levy captured its glimpse in their Sclamidt telescope. During 16-22 July, 1994 it collided with the massive planet Jupiter.

In this collision no harm was done to the Jupiter, It was the first event of collision, of two components of the solar system seen from the Earth.

26. Meteor is a [I.A.S. (Pre) 1995]

Correct Answer: (b) A picce of matter which has entered the earth atmosphere from outer space
Solution:A meteor is a bright streak of light in the sky also called a shooting star or a falling star but actually, it is a not a star but just a small piece of rocks and minerals.

It starts glowing because when it enters into the Earth's atmosphere with a very high velocity it burns due to heat caused by air friction. Most of the meteors burn to ashes before reaching upon the surface of the Earth.

27. Correct Latitudinal position of a place that could be possible is- [R.A.S./R.T.S. (Pre) 1999]

Correct Answer: (c) 45° South
Solution:Latitudes in the Greek language are generally denoted by the letter. It shows the places towards North and South of Equator. 90° Northern latitude is called the North Pole while 90° Southern latitude is called the South Pole which are just points not the circle, but other latitudes on both sides of Equator are imaginary circles.

East and West of Prime Meridian are total 360 longitude. So, in above option obiviously 45° East and 91° West are representing longitudinal positions and 91º North has no meaning. Therefore 45° South represents the correct latitudinal position of a place.

28. Which of the following is not a great circle on the globe? [Uttarakhand U.D.A./L.D.A. (Pre) 2003]

Correct Answer: (d) 60° North latitude
Solution:A great circle is that line which divides a sphere into two hemispheres. Upon the Earth, all the meridians longitudes and the Equator are great circles. Except for equator no other latitude is a great circle because they are smaller in comparison to the Equator.

29. Zero degree latitude and zero degree longitude lies in the [Uttarakhand P.C.S. (Pre) 2005]

Correct Answer: (a) Atlantic Ocean
Solution:The point at which Equator (0º latitude) and the Prime Meridian (0º longitude) intersect has no real significance but it is in the Gulf of Guinea in the Atlantic Ocean, so the correct option is (a).

30. Point of intersection of the Equator and the Prime Meridian is located at- [U.P. Lower Sub. (Pre) 2009]

Correct Answer: (a) Atlantic Ocean
Solution:The point at which Equator (0º latitude) and the Prime Meridian (0º longitude) intersect has no real significance but it is in the Gulf of Guinea in the Atlantic Ocean, so the correct option is (a).