Daily Quiz: UPSC Prelims Marathon – August 17, 2018

Statement 1 is incorrect.

Earthquakes is caused by all types of plate boundaries i.e. Convergent boundaries (where two plates are colliding); Divergent boundaries (where two plates are moving apart) and Transform boundaries (where plates slide passed each other).

Statement 2 is correct.

The first kind of body wave is the P wave or Primary wave. This is the fastest kind of seismic wave, and, consequently, the first to ‘arrive’ at a seismic station. The P wave can move through solid rock and fluids, like water or the liquid layers of the earth.

The second type of body wave is the S wave or secondary wave, which is the second wave you feel in an earthquake. An S wave is slower than a P wave and can only move through solid rock, not through any liquid medium.

Surface Waves travels only through the crust. It is surface waves that are almost entirely responsible for the damage and destruction associated with earthquakes. This damage and the strength of the surface waves are reduced in deeper earthquakes.

Surface waves are of a lower frequency than body waves, and are easily distinguished on a seismogram as a result.

Statement 3 is incorrect.

Time and location of most major earthquakes cannot be predicted several days in advance.

All the pairs are correctly matched.

Statement 1 is incorrect.

The temperate deserts are rainless because of either continentality or rain-shadow effect. For example, the Gobi Desert is formed due to continentality and Patagonian Desert due to rain- shadow effect. The Patagonian Desert is more due to its rain-shadow position on the leeward side of the lofty Andes than to continentality.

Statement 2 is correct.

The predominant vegetation of both hot and mid-latitude deserts is xerophytic or drought- resistant. This includes the cacti, thorny bushes, long-rooted wiry grasses and scattered dwarf acacias. Trees are rare except where there is abundant groundwater to support clusters of date palms.

Statement 3 is correct.

Most of the world’s hot deserts lie between 15° N and 30° S on the western margins of the continents. They owe their location to five factors:

1. Deserts are areas of high pressure and subsiding air not conducive to cloud formation or rainfall.
2. Dry offshore Trade winds blow in winters.
3. Rain shadow effect is felt where the mountains block the moisture-laden winds on the western margins of the continents.
4. Cold currents wash the coast on the western sides of the continents making th e onshore winds stable.
5. Winds blow out of this belt, that is, the Trade winds and the Westerlies diverge.

At low latitudes the tropical hot deserts occur in the areas of subtropical high where subsidence of vertical air currents and inversion of temperature prevent the occurrence of rainfall. Under the influence of cold ocean currents, on the west coast of south America they extend more towards the Equator.

Statement 1 is incorrect.

In general, cyclones are associated with clouds, rain and thunderstorms while anticyclones are associated with fair weather.

Before cloud formation, water takes up heat from the atmosphere to change into vapour. When water vapour changes back to liquid form as raindrops, this heat is released to the atmosphere. The heat released to the atmosphere warms the air around. The air tends to rise and causes a drop in pressure. More air rushes to the centre of the storm. This Cycle is repeated. The chain of events ends with the formation of a very low-pressure system with very high-speed winds revolving around it.

Factors like wind speed, wind direction, temperature and humidity contribute to the development of cyclones.

In case of anticyclones the air sinks, it warms and dries. This produces clear skies and increases the air’s ability to transmit radiant energy.

Statement 2 is correct.

The primary difference between the two types of weather systems is their atmospheric pressure. Cyclones represent areas of low pressure, while anticyclones represent areas of high pressure.

Statement 1 is correct.

The thickness of Troposphere is greater at the equator, because the heated air rises to greater heights.

Statement 2 is incorrect.

waves transmitted from the earth are reflected back to the earth by this layer.

Statement 3 is correct.

Atmospheric pressure is the weight of the atmosphere on a surface. The units for atmospheric pressure are conveniently known as atmospheres (atm) and the average pressure at sea level is set at 1 atmosphere (atm). The atmospheric pressure at any given point depends on two factors: Altitude – the height of a thing in relation to sea level

Temperature – the intensity of heat

Statement a is incorrect.

It is Fog, not mist. Fogs are prevalent where warm currents of air come in contact with cold  currents. Fogs are drier than mist.

Statement b is incorrect.

As the cold air streams across the warm lakes, it is warmed and becomes more humid. As the air warms, it becomes less dense and tends to rise cooling (as it rises). Whenever moist air rises, as previously noted, clouds may form and precipitation may result. Fog results from the intense evaporation or transfer of moisture from the warm water to much colder air when the cold air initially makes contact with warm water. After the air passes from some distance over the lake, convection and turbulent exchange have transported the acquired moisture aloft to form clouds and snowfall may occur.

Statement c is incorrect.

The adiabatic cooling of air below its dew point leads to formation of Clouds.

Statement d is correct.

Mists are frequent over mountains as the rising warm air up the slopes meet a cold surface. Mist is also formed by water droplets, but with less merging or coalescing. This means mist is less dense and quicker to dissipate. In mist visibility is more than one kilometre but less than two kilometres.

Statement 1 is incorrect.

When the position of both the sun and the moon in relation to the earth has direct bearing on tide height. When the sun, the moon and the earth are in a straight line, the height of the tide will be higher. These are called spring tides and they occur twice a month, one on full moon period and another during new moon period.

Statement 2 is correct.

Neap tides occur when the Sun and Moon are at right angles to each other and the forces of the Sun and Moon tend to counteract one another.

The height of rising water (high tide) varies appreciably depending upon the position of sun and moon with respect to the earth. Spring tides and neap tides come under this category.