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- Question 1 of 50
The atmosphere is heated mainly by:
The atmosphere is heated mainly by the Radiation from the Sun. This radiation when passes through the atmosphere is absorbed by soil, plants, water bodies, the air molecules.
- Question 2 of 50
A device used for converting AC into DC is called:
A rectifier is a special type of diode that converts alternating current (AC) into direct current (DC).
- Question 3 of 50
Energy of Ultraviolet rays is greater than:
Energy of Ultraviolet rays is greater than Infrared rays. Radio waves have photons with the lowest energies. Microwaves have a little more energy than radio waves. Infrared has still more, followed by visible, ultraviolet, X-rays and gamma rays. Cosmic rays are (not part of the electromagnetic spectrum) high-energy outer space particles.
- Question 4 of 50
To an astronaut, the sky appears:
The sky appears blue when the scattering of light takes place. As there is no atmosphere in space and hence light does not scatter into its constituent colors that is why the sky appears dark instead of blue to an astronaut in space.
- Question 5 of 50
The instrument used to measure the speed of the wind is:
An anemometer is an instrument that measures wind speed and wind pressure. Anemometers are important tools for meteorologists, who study weather patterns.
- Question 6 of 50
Who defined the law of gravitation?
law of gravitation is defined by Isaac Newton in 1687. Newton’s law of universal gravitation is usually stated as that every particle attracts every other particle in the universe with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
- Question 7 of 50
The metal used to make lightning conductors is:
The main attribute common to all lightning rods is that they are all made of conductive materials, such as copper and aluminum. Copper and its alloys are the most common materials used in lightning protection.
- Question 8 of 50
‘IC’ in computers stands for:
An integrated circuit (IC) is a set of electronic circuits on one small flat piece of semiconductor material, usually silicon. IC can function as an amplifier, oscillator, timer, microprocessor, or even computer memory.
- Question 9 of 50
A hydrogen balloon floats up because of:
Hydrogen is lighter than air. When a ballon is filled with hydrogen gas the weight of the ballon is less than the weight of air displaced by the ballon.
- Question 10 of 50
In a rechargeable cell what kind of energy is stored within the cell?
In a rechargeable cell, chemical energy is stored within the cell. Chemical energy is energy stored in the bonds of atoms and molecules. Batteries, biomass, petroleum, natural gas, and coal are examples of chemical energy.
- Question 11 of 50
Which one of the following lenses should be used to correct the defect of astigmatism?
A cylindrical lens can be used to treat astigmatism. Astigmatism is a condition that results in the abnormal curvature of your cornea or the lens of your eye.
- Question 12 of 50
Superconductors are those elements:
Superconductors are those elements whose resistance falls almost to zero at very low temperatures. Superconductivity is complete disappearance of electrical resistance in various solids when they are cooled below a characteristic temperature.
- Question 13 of 50
Suppose if we measure the time lapse between the two Sunsets by sitting on the beach, from this we can estimate:
From this, we can estimate the radius of the earth as the point of the horizon must cover the circumference of the Earth.
- Question 14 of 50
In a Laser (say neon laser) all the atoms emit the light waves of:
The major difference between laser light and other light sources (such as a light bulb) is that laser light is monochromatic, directional and coherent. Monochromatic means that all of the light produced by the laser is of the same frequency, amplitude and phase.
- Question 15 of 50
Which of the following has got more heat capacity:
Liquid water has one of the highest specific heat capacities among common substances, about 4184 J⋅kg−1⋅K−1 at 20°C; but that of ice, just below 0°C, is only 2093 J⋅kg−1⋅K−1. Hydrogen gas has more than three times (14300 J⋅kg−1⋅K−1) the specific heat as water under normal laboratory conditions.
- Question 16 of 50
Of the following Indian satellites, which one is intended for long distance telecommunication transmitting TV programmes?
INSAT-1A was an Indian communications satellite, Launched in 1982. The Indian National Satellite System (INSAT) is a series of multipurpose geostationary satellites launched by ISRO to satisfy the telecommunications, broadcasting, meteorology, and search and rescue operations.
- Question 17 of 50
What is the full form of ‘AM’ regarding radio broadcasting?
Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave.
- Question 18 of 50
Which colour is the complementary colour of yellow?
Complementary colors are pairs of colors which, when combined or mixed, cancel each other out by producing white or black. Examples of complementary color combinations are: Red and green; yellow and blue (purple).
- Question 19 of 50
During washing of clothes, we use indigo due to its:
During washing of clothes, we use indigo due to its proper pigmental composition. The combination of yellow and blue colours gives white colour. Hence we add blue indigo to remove yellow tint from the white clothes.
- Question 20 of 50
The energy stored in a watch spring is:
Potential energy is the stored energy in any object or system by virtue of its position or arrangement of parts. The energy stored in a watch spring is potential energy. When a spring is compressed, it stores energy in form of elastic potential energy.
- Question 21 of 50
Which one of the following acids is used in battery?
Battery acid is sulphuric acid that has been diluted with water to attain a 30-40% concentration level.
- Question 22 of 50
The sensation of weightlessness in a spacecraft in an orbit is due to the:
Reason of weightlessness in a spacecraft is Zero reaction force by spacecraft surface. When spacecraft is moving with constant speed along the orbit, the spacecraft as well as the person inside it, both fall towards the earth with acceleration ‘g’.
- Question 23 of 50
‘Therm’ is the unit of:
‘Therm’ is a non-SI unit of heat energy. 1 therm is equal to 100000 British thermal units (BTU).
- Question 24 of 50
Cream gets separated out from milk when it is churned. This is due to:
Milk is put in a container in a centrifuge machine and the container is spun at a very high speed. The centrifugal forces act on milk and separate the milk into a cream that is lighter thus floats on top and skimmed milk which is at the bottom. Then cream can be separated from the milk.
- Question 25 of 50
Newton’s first law of motion gives the concept of:
Newton’s First Law, sometimes referred to as the law of inertia, describes the influence of a balance of forces upon the subsequent movement of an object.
- Question 26 of 50
The process by which the sun’s rays reach the earth is:
Energy is transferred from the sun to Earth via electromagnetic waves, or radiation. Radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium.
- Question 27 of 50
A pond of water appears less deep due to:
A pond of water appears less deep due to refraction. A pond of water appears to be less deep than it actually is because light rays from the bottom of the pond are bent away from the normal as they pass from water into the air. This makes the pond appear shallower than it really is.
- Question 28 of 50
The oldest type of energy known to man is:
The oldest type of energy known to man is geothermal energy. Geothermal energy is heat (thermal) derived from the earth (geo). Archaeological evidence shows that the first human use of geothermal resources in North America occurred more than 10,000 years ago with the settlement of Paleo-Indians at hot springs.
- Question 29 of 50
Water pipes in hilly areas often burst on a cold frosty night, because:
Water pipes in hilly areas often burst on a cold frosty night, because water in the pipes freezes and on freezing water expands in its volume, causing a significant amount of pressure buildup, so pipes break.
- Question 30 of 50
A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because:
A parachute descends much slower than stone because the surface area of the parachute is larger than the stone so air gives more resistance when it descends down.
- Question 31 of 50
Which of the following instruments is used to measure relative humidity?
A sling psychrometer can be used to find relative humidity, which is expressed as a percentage.
- Question 32 of 50
The period of revolution of a geostationary satellite is:
A geostationary satellite is an earth-orbiting satellite, placed at an altitude of approximately 35,800 km directly over the equator, that revolves in the same direction the earth rotates (west to east). At this altitude, one orbit takes 24 hours, the same length of time as the earth requires to rotate once on its axis. So they seem stationary, relative to the Earth’s surface.
- Question 33 of 50
The type of mirrors used in the headlamp of cars is:
A parabolic concave mirror is used in torches and car headlamps as reflectors. This type of mirror is capable of directing the light at a particular point as they have converging power. These mirrors provide clear visibility.
- Question 34 of 50
The reason for a swimming pool to appear less deep than the actual depth is:
A swimming pool appears less deep due to refraction. The swimming pool appears to be less deep than it actually is because light rays from the bottom of the pool are bent away from the normal as they pass from water into the air. This makes the pool appear shallower than it really is.
- Question 35 of 50
Alternating current is converted into direct current by a:
Rectifier is device that converts alternating electric current into direct current.
- Question 36 of 50
Flat-footed camels can walk easily in sandy deserts because:
Flat-footed camels can walk easily in sandy deserts because the pressure per unit area on the sand is decreased by increasing the area of the surface in contact.
- Question 37 of 50
Which of the following is most elastic?
Elasticity is an ability of a deformed material body to return to its original shape and size when the forces causing the deformation are removed. It is measured as the ratio of stress to strain (modulus of elasticit).
- Question 38 of 50
When a person walking in bright Sunlight enters a dark room, he is not able to see clearly for a little while because:
When a person walking in bright Sunlight enters a dark room, he is not able to see clearly for a little while because the iris is unable to dilate the pupil immediately.
- Question 39 of 50
The swing of a spinning cricket ball in the air can be explained on the basis of:
The swing of a spinning cricket ball in the air can be explained on the basis of turbulence caused by wind.
- Question 40 of 50
The freezer in a refrigerator is fitted near the top:
The freezer in a refrigerator is fitted near the top so that it can cool the whole interior by setting up convection currents. The natural law of convection is that warm air rises while cold air falls, so the freezer at the top provides cold air for the other compartments at the bottom of the freezer.
- Question 41 of 50
Why two thin shirts can keep us warmer than a single thick shirt in winter?
The air layer between two shirts behaves like insulating media. Air in general is a good thermal insulator, but it can transmit heat through convection. However, if the air pockets inside the insulating material are separated from each other, heat flow from one air pocket to another cannot happen easily.
- Question 42 of 50
Sound cannot pass through:
Sound cannot pass through vacuum. This is because sound waves are mechanical waves that need a medium (such as air, steel and water) to travel.
- Question 43 of 50
Water is not effective in extinguishing a fire caused by petrol because:
Water and petrol are immiscible with each other and petrol which forms the upper layer continues to burn. Water is heavier than petrol, petrol will come above the water and continue the contact with the atmosphere (oxygen).
- Question 44 of 50
An egg sinks in soft water but floats in a concentrated solution of salt because:
The egg is denser than the soft water, this causes it to sink. Dissolving salt in the water increases the density (adding more molecules per square inch).
- Question 45 of 50
What should a person on a freely rotating turntable do to decrease his (angular) speed?
Spread his hands outwards should a person on a freely rotating turntable do to decrease his (angular) speed. A person on the rotating table will maintain approximately the same angular momentum during the spin. When he spreads his hands outward, the angular rotation is decreased.
- Question 46 of 50
Which of the following celestial bodies contains abundant quantities of helium-3, a potential source of energy?
Helium-3 is a gas that has the potential to be used as a fuel in future nuclear fusion power plants. There is very little helium-3 available on the Earth. However, there are thought to be significant supplies on the Moon.
- Question 47 of 50
Which of the following circuit elements is used to block DC in an electronic circuit?
A capacitor blocks direct current (DC) and allows alternating current (AC) to pass through it. An inductor does not allow AC but allows DC to pass through it. A Diode converts AC into DC. Resistors are used to reduce current flow.
- Question 48 of 50
Spectacles used for viewing 3D films have:
Spectacles used for viewing 3D films have Polarised lenses. They have a special film which is used to view 3D films. Polarised 3D Spectacles are the kind typically used in modern movie theaters.
- Question 49 of 50
A boy sitting in an open car moving with constant speed throws a ball straight up into the air. The ball falls:
Due to inertia of motion, as long as the ball stays in the air, both the boy and the ball move in the same direction which cause the ball falls into his hand.
- Question 50 of 50
Detergents clean surface on the principle of:
Detergents clean surfaces or clothes on the principle of surface tension. Adding detergent to water reduces its surface tension.