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Correct answer is (a) By insulation

To elaborate: HEAT is TRANSFERRED from the absorber plate to a point of USE by the circulating fluid via water ACROSS the solar heated surface. The heat loss from the surface is prevented by placing thermal insulation of 5 to 10cm THICKNESS behind the absorber plate.

Correct answer is (d) Pyrheliometer

To EXPLAIN I WOULD say: A Pyrheliometer is the DEVICE USED to MEASURE direct beam solar irradiance. Sunlight enters the instrument through a window and is directed onto a thermopile which converts heat to an electrical signal that can be recorded.

Correct choice is (a) 2

Explanation: Based on the type of heat transfer fluid, flat plate collectors are divided into TWO TYPES, they are LIQUID Heating Collectors and Air or gas heating collectors. And ALSO happens that all other types of collectors come under these two types.

The CORRECT option is (b) Zenith angle

Easiest explanation: The angle between the sun’s rays and a LINE perpendicular to the horizontal plane through angle MEASURED from the NORTH to the horizontal projection of rays is called zenith angle. And it is denoted by θz.

Correct choice is (a) HEATING water

Explanation: Liquid heating collectors are mainly used for heating water. A liquid based SOLAR collector is a solar collector that uses sunlight to heat a liquid that is CIRCULATING in a solar loop. The fluid in the solar loop may be water, an anti freeze MIXTURE or thermal oil.

The CORRECT answer is (c) -23.45^o

For EXPLANATION: In the CASE γ = 0^o, on December 21, n=355

The correct CHOICE is (d) Transparent cover

Explanation: A transparent cover is glazing which limits the radiation and heat convection losses. It includes one or more SHEETS of glass or radiation TRANSMITTING plastic film or sheet. The glass itself is ALWAYS a single pane adding to adding the second REDUCES the collector efficiency.

Right ANSWER is (a) DECLINATION

For explanation: Declination is the ANGULAR distance of sun’s rays north or south of the equator. It is the angle between the line extending from the centre of the sun to the centre of the earth and the PROJECTION of this line upon earth’s equatorial plane.

Correct choice is (a) 3.8 X 1024 J/year

For explanation: Even if we use 5% of this energy, it is more than 50 TIMES our REQUIREMENT. The total solar radiation absorbed by the earth and its atmosphere is 3.8 X 1024 Joules/year. EXCEPT that it is DISTRIBUTED over the AREA of earth.

The correct choice is (a) Zenith

The explanation is: When the SUN is DIRECTLY on the top of the head, it is referred to as sun at zenith. The zenith is an IMAGINARY point directly “above” a particular location, on the imaginary celestial sphere. The zenith is the “highest” point on the celestial sphere.

Correct ANSWER is (a) INSOLATION

The best explanation: Insolation is the total solar radiation received at any point on any point on the earth’s surface. In other words insolation is the SUM of the direct and diffuse radiation. More specifically insolation is defined as the total solar radiation ENERGY received on a horizontal surface of unit area on the ground in unit time.

Correct option is (b) Non-porous ABSORBER plate

To elaborate: In a simple flat plate AIR collector, commonly known as non-porous absorbers, the air STREAM flow through the absorber plate without any obstruction. An analysis of black PAINTED solar air collectors in conventional design in which the air flows below the absorber plate has been MADE.

The correct choice is (a) Solar AZIMUTH angle

Easy explanation: The solar angle in degrees ALONG the horizon east or west of north or it is the horizontal angle measured from north to the horizontal PROJECTION of SUN’s rays is called solar azimuth angle. And it is DENOTED by Greek letter γs (GAMMA).

Correct option is (a) 1016W

Explanation: The solar energy REACHING the surface of the earth is about 1016W whereas the WORLDWIDE power DEMAND is 1013W. That means solar energy GIVES us 1000 TIMES more energy than our requirement.

Correct answer is (a) Solar ENERGY

For explanation: Solar energy has the greatest potential of all the sources of renewable energy which COMES to the EARTH from sun. This energy keeps the temperature of the earth above that in COLDER space, causes wind currents in the ocean and the atmosphere, causes WATER cycle and generates photosynthesis in plants.

Right answer is (C) EMPLOYED as solar air heaters

Best explanation: Air or Gas heating COLLECTORS are employed as solar air heaters. Solar air heater is a type of system driving OUTDOOR air through a sealed, sun heated COLLECTOR mounted on an exterior wall or roof, returning the warmed air back to the living space.

Right choice is (a) Slope

Easy EXPLANATION: The slope is the angle made by the plane surfaces with the horizontal. It is considered positive for surfaces SLOPPING TOWARDS the south and negative for SURFACE slopping towards the north. Different types of measurements are calculated by SLOPES.

Right option is (a) Solar intensity

To EXPLAIN I would say: The solar intensity at a direction normal to the tilted surface is the vector sum of the COMPONENTS ALONG the line normal of the tilted surface. And is GIVEN by formula,

IΣ = IDN cosθΣ

Where IDN = solar intensity IRRADIATED on a surface normal to the sun’s rays.

Right option is (a) Latitude

The explanation is: Angle made by radial line joining the location to the centre of the EARTH with the projection of the line on the EQUATORIAL plane is called latitude. And it is denoted by Φl. It is also given by the angular DISTANCE north or south of the EQUATOR measured from the centre of the earth.

Correct answer is (b) Solar constant

For explanation: The AMOUNT of energy received in unit time on a unit area perpendicular to the sun’s direction at the MEAN distance of the earth from the sun is CALLED solar radiation. It is defined as the solar energy receiving at the TOP of the atmosphere, denoted by Isc.

The correct answer is (b) Spent fuel

The BEST I can explain: Spent fuel is the UNPROCESSED fuel that is removed from the reactor CORE after reaching end of core LIFE service. It is removed and then stored for 3 to 4 months under water in the plant SITE to give time for the most intense radioactive isotopes to decay.

Correct ANSWER is (b) Local solar temperature

Easy explanation: Local solar time is ALSO known as local apparent time which is the time used for calculating the hour angle. The local solar time is OBTAINED from the standard time OBSERVED on a clock by making two corrections. First, is taking different longitudes between the locations and second is correction due to small perturbations of earth’s orbit and rate of rotation.

The correct answer is (a) SURFACE azimuth angle

The best I can explain: Surface azimuth angle is the angle of deviation of the normal to the surface from the local MERIDIAN, the zero point being SOUTH, east positive and west negative. And surface azimuth is different where it is an angle on a horizontal plane between the normal to a vertical surface and the north-south direction LINE.

The CORRECT CHOICE is (a) Hour angle

Easy explanation: The angle through which the earth must turn to bring the meridian of a point directly in SUN’s rays is called Hour angle. And it is denoted by Greek letter ω (OMEGA). It is MEASURED from noon based on the solar LOCAL time (LST).

The correct choice is (a) POROUS absorber plate

For EXPLANATION I would SAY: In the porous BED air heater, the matrix material is ARRANGED and the back absorber plate is eliminated. A single glazed porous bed collector with a reflecting honey comb, extending above the porous to just under the glass cover have theoretically examined.

Correct answer is (c) Insulation

Easy explanation: Insulation is provided at the BACK and sides to minimize heat losses. Fiber GLASS or styro-foam is used for this purpose. And also most MODERN collectors USE standard INSULATORS such as polyurethane or polyisocynurate.

The correct option is (a) Magneto HYDRO Dynamic

To explain: Magneto hydro dynamic is a generator which is used for direct CONVERSION of thermal ENERGY into electrical energy. They work on faraday principle. When an electric CONDUCTOR moves across a magnetic field, electric current is produced.

The correct option is (C) Electromagnetic waves

To EXPLAIN: Solar energy is radiated from the sun in the form of electromagnetic waves of shorter wavelength of 0.2 to 0.4 MICROMETERS. Out of all the solar energy radiations reaching the earth’s atmosphere, 8% is ultraviolet radiation, 40% is visible range light and 46% is by infrared radiation.

Correct answer is (a) PYRANOMETER

For EXPLANATION I would say: A Pyranometer is a type of actinometer used for measuring solar IRRADIANCE on a planar surface and it is designed to measure the solar radiation flux DENSITY from the HEMISPHERE above within a wavelength range 0.3μm to 3μm.

Right answer is (B) Altitude ANGLE

To elaborate: The vertical angle between the PROJECTION of the sun’s rays on the horizontal plane and the direction of sun’s rays passing through the point s called solar altitude and is ALSO referred to altitude angle and is denoted by Greek letter α (ALPHA).

The correct option is (b) HIGH Level Waste

For explanation I would SAY: These are generated in reprocessing of SPENT fuel. They contain all fission PRODUCTS and contain of the transuranium elements not separated during reprocessing. Such wastes are to be disposed of carefully.

The correct choice is (a) 100 years

To EXPLAIN I would say: ALMOST 40% of energy NEEDS is met by oil alone. With present consumption and a RESOURCE of 250,000 million tonnes of oil, it is estimated to be LAST for only 100 years, unless more oil is discovered. Major chunk of oil comes from petroleum.

Right choice is (b) ABSORBER plate

The EXPLANATION is: Absorber plate is usually metallic or COATED in black surface which is used for absorbing RADIATION energy. The absorber plate’s coating directly affects how efficient the collector is. Coatings ALWAYS have two rating figures: how much they absorb and how much they emit.

The correct answer is (a) ICosθ

To elaborate: I = ICosθ, Let θ = Angle between an INCIDENT beam radiation I and the normal to the PLANE surface. And the θ is REFERRED to as incident angle. And further by this formula latitude angle, declination, hour angle, zenith angle and solar AZIMUTH ANGLES are found out.

The CORRECT answer is (a) δ

Easy EXPLANATION: Solar declination is denoted by Greek letter δ(DELTA). Solar declination is the ANGLE between the earth-sun LINE and the equatorial plane. Solar declination varies throughout the year. And is given by cooper equation,

δ = 23.45sin [(360/365) (284+n)] ∵n is day of the year.

The correct answer is (c) DIFFUSE radiation

Best EXPLANATION: Diffuse radiation received from the sun after its direction has been CHANGED by reflection and scattering by the ATMOSPHERE. Since the solar radiation is scattered in all direction in the atmosphere, diffuse radiation comes to the EARTH from all parts of the sky.

Right answer is (B) ROENTGEN

Explanation: Units of nuclear radiation is Roentgen- AMOUNT of radiation which will on passing through pure air under standard CONDITION produce 1 electrostatic unit of ions/cm^3 of air -> 86.9 ergs of energy absorbed/gm of air.

The correct choice is (C) Coal

For explanation: Coal is the most common source of energy that is being used since industrialization. Modern steam boilers can BURN coal in any of its FORM as a PRIMARY fuel. DIFFERENT ranks of coal available are peat, lignite, bituminous and anthracite.