Daily Quiz: UPSC Prelims Marathon – July 13, 2018

Maize, Sorghum and soyabean are cultivated through direct Seeding whereas onion is cultivated by transplanting seedlings.

The rivers marked are

1. Kosi
2. Gomati
3. Ghaghara
4. Gandak

Tropical cyclones are not formed near the equator because coriolis force is absent. At the equator, coriolis force is zero and the wind blows perpendicular to the isobars. The low pressure gets filled instead of getting intensified. This is the reason why tropical cyclones are not formed near the equator. Hence statement (b) is correct.

Knowledge Base) Force exerted by the rotation of earth is called coriolis force. It deflects the wind to the right direction in the northern hemisphere and to the left in the southern hemisphere. The deflection is more when the wind velocity is high. The coriolis force is directly proportional to the angle of latitude. It is maximum at the poles and is absent at the equator.

During its revolution around the sun, the earth is farthest from the sun (152 million km) on 4th July. This position of the earth is called aphelion. On 3rd January, the earth is the nearest to the sun (147 million km). This position is called perihelion.

The implementation of Ken-Betwa Link project will submerge 55.78 sq km (10.07%) of critical tiger habitat (CTH) of the Panna tiger reserve and national park.  Hence, option (b) is correct.

A-77 metre high dam, namely Daudhan is proposed across river Ken, about 2.5 km upstream of existing Gangau Weir on Ken River. The reservoir involves a submergence of 9000 hectare area, out of which 5803 hectare comes under the tiger reserve, drawing the ire of the local people.

Earth’s magnetic field is always existent because of presence of molten iron in the core. It does not depend on the speed of rotation of molten iron. Thus, only statement 3 is incorrect. Rest all statements are correct. Hence, option (c) is correct.

Knowledge Base) Earth’s magnetic field is used in mariner’s compass by travelers to navigate around earth. Thus, statement (1) is correct.

The Earth’s magnetic field serves to deflect most of the solar wind, whose charged particles would otherwise strip away the ozone layer that protects the Earth from harmful ultraviolet radiation. Thus, statement (2) is correct.

A geomagnetic reversal is a change in a planet’s magnetic field such that the positions of magnetic north and magnetic south are interchanged, while geographic north and geographic south remain the same. The Earth’s field has alternated between periods of normal polarity, in which the predominant direction of the field was the same as the present direction, and reverse polarity, in which it was the opposite. These periods are called chrons. Thus, statement (4) is correct.

Metamorphism occurs when rocks are forced down to lower levels by tectonic processes or when molten magma rising through the crust comes in contact with the crustal rocks or the underlying rocks are subject to great pressure by overlying rocks. Since all these processes happen inside earth’s crust, statement (1) is correct.

In the process of metamorphosis, some rock grains or minerals get arranged in layers or lines. This is called foliation or lineation.

Similarly, groups of minerals are deposited in alternate layers of light and dark colors. This is called banding. Thus, statement (2) is also correct.

Hence option (d) is correct.