Ans. (d)

Explanation

The Scholar suggested the earth's origin from gases and dust particles is O. Schmidt. He propounded "Inter Stellar dust hypothesis".

James Jeans - Tidal hypothesis

H. Alfven - Intestellar cloud hypothesis

F. Hoyle - Super nova hypothesis.

Ans. (c)

Explanation

The correct sequence is Tropo - Strata - Meso - Iono spheres.

Troposphere extends upto 8-18 km, after that, Stratosphere upto 50 km, after that Mesosphere extends upto 80 km and beyond that, upto 400 km Ionosphere exists.

Ans. (b)

Explanation

Daily weather map showing isobars i.e. places having equal pressure is an example of Isopleth map.

Ans. (b)

Explanation

Indian Subcontinent (in north), Africa (in west) and Australia (in South East) are the land regions that are located around the Indian ocean. Due to the monsoon drift, ocean current in the Indian ocean becomes eastward and westward in June and November respectively. It is affected by wind circulation.

Ans. (c)

Explanation

The most relevant condition for the presence of life on Mars is occurence of ice caps and frozen water. Because the same situations, on the earth also, are supposed to support the 'primitive forms of life.

Ans. (d)

Explanation

The group of small pieces of rocks revolving round the Sun, between the orbits of Mars and Jupiter are called Asteroids. They may be about 1,00,000 in numbers but their total mass is only a few hundredths the mass of Moon. They include Ceres (the largest - 940 kms in diametre), Vesta (has a light coloured surface and brightest as seen from the Earth), Eros and Icarus.

Ans. (a)

Explanation

1, 2, 3 statements are correct but not 4. Because, the magma solidified between sedimentary rocks in a horizontal position is known as "Sill", but not Dyke (Dyke - solidification in vertical position).

Ans. (c)

Explanation

Because of its high density, a black hole has very high gravitational force. So no object, whether it is particle or light, can escape from it.

Ans. (c)

Explanation

Sun is the nearest star of earth, with its average distance being 149-6 million km and proxima centauri is the second nearest star of the earth.

Ans. (b)

Explanation

Oxygen, in the form of oxides, is present in the largest amounts, second abundant is Silicon, third abundant is Aluminium, in the earth's crust.