GC Leong Test: The Oceans - Super TET MCQ

• The profound influence of climate and weather over man's activities can be seen from his everyday life.

• Forces of nature have regulated to a very great extent the sort of food we eat, what we wear, how we live and work. 

• Our mental alertness, physical characteristics, and even our racial differences when closely examined have some relationship with climate. 

• The direction of winds once controlled the pattern of trading routes. The safety of modern air communications is closely tied to accurate meteorological reports from the ground stations. 

• Despite the advances made in science and technology, farmers and their crops are still at the mercy of the climate and the weather. 

• Conditions of temperature, precipitation and humidity may promote or discourage fungus and diseases which may be injurious to both men and crops. 

• Death rates are normally high in tropical countries and low in deserts because germs are not transmitted readily in high temperature and low humidity. Cool, fresh mountain air is always good for health.

• Rainfall, including other precipitation forms (snow, sleet and hail) is always measured by a metal instrument called a rain gauge. 

• It consists of a copper cylinder with a metal funnel either 5 inches or 8 inches in diameter, leading to a smaller copper container or a glass bottle. 

• The hole in the funnel that leads down to the container is very small so that evaporation of the collected rain is minimised. The gauge should be at least one foot above the ground.

• On maps, places of equal pressure are joined by lines called isobars. In temperate latitudes, pressure changes are very rapid. in the formation of cyclones and anticyclones. 

• In normal circumstances, they vary from 960 Mb. to 1,040 Mb. 

• Pressure readings vary with several factors. A sea-level reading of 30 inches will be halved on mountainous regions of 3.5 miles above sea level. 

• This is because as one ascends there is less air above and so the weight, or pressure is less. The barometer is also sensitive to gravitational forces at different latitudes.

Tiny Builders Coral reefs are built by and made up of thousands of tiny animals—coral “polyps”—that are related to anemones and jellyfish.

Coral polyps are tiny, soft-bodied organisms related to sea anemones and jellyfish. At their base is a hard, protective limestone skeleton called a calicle, which forms the structure of coral reefs. 

Under favourable conditions, they grow in great profusion just below the water level. Taking coral animals as a whole, the polyps are the most abundant and also the most important. Each polyp resides in a tiny cup of coral and helps to form coral reefs. When they die, their limy skeletons are cemented into coralline limestone.

• Temperature is an essential element of climate and weather. The instrument for measuring temperature is the thermometer is a narrow glass tube filled with mercury or alcohol. 

• It works on the principle that mercury expands when heated and contracts when cooled. On thermometers, temperatures are marked in one of two ways. In °F. (Fahrenheit), the freezing-point is 32°F. and the boiling-point is 212°F. 

• For most scientific purposes the Centigrade °C. Scale is preferred. Its freezing-point is 0°C., and its boiling-point is 100°C. The mean daily temperature of Malaysia is 80°F. or 26.7°C.

• The difference between the maximum and minimum temperatures of a day gives the diurnal range of temperature. 

• The difference between the hottest month (i.e. July in the northern hemisphere) and the coldest month (i.e. January in the northern hemi-sphere) gives the annual range of temperature. 

• In diagrammatic representations, monthly mean temperatures are shown in simple temperature graphs or in temperature distribution maps as isotherms

• Humidity is a measure of the atmosphere's dampness, which varies greatly from place to place at different times of day. 

• The actual amount of water vapour present in the air, which is expressed in grams per cubic metre, is called the absolute humidity. 

• But more important from the point of view of weather studies is the relative humidity. 

• This is the ratio between the actual amount of water vapour and the total amount the air can hold at a given temperature, expressed as a percentage. 

• Warm air can hold more water vapour than cold air, so if it contains only half the amount it could carry, the relative humidity is 50 per cent. 

• In the equatorial regions, over 80 per cent is common in the morning, which means the air contains four-fifths as much water vapour as it can carry. 

• When air rises, it is cooled by expansion. After dew-point has been reached, cooling leads to condensation of water vapour in the atmosphere. 

• Tiny droplets of water vapour which are too small to fall as rain or snow (less than 0.001 cm., approximately 0.0005 inches in radius) will be suspended in the air and float as clouds. 

• Their form, shape, height and movements tell us a great deal about the sky conditions and the weather we are likely to experience. It is fascinating and gratifying to know something about the clouds which we see every day.

• Cirrus (Ci): This looks fibrous and appears like wisps in the blue sky; it is often called 'mares' tails'. It indicates fair weather and often gives a brilliant sunset. 

• Cirrocumulus (CC): This appears as white globular masses, forming ripples in a mackerel sky. 

• Cirrostratus (Cs): This resembles a thin white sheet or veil; the sky looks milky and the sun or moon shines through it with a characteristic 'halo'

Mist: 

• The condensation of water vapour in the air causes small droplets of water to float about forming clouds at ground level called mist. It reduces visibility to about 1,000 metres or 1,100 yards.

• Unlike haze, mist occurs in wet air, when the relative humidity is over 75 per cent.