Every Day Science Paper - 1996
Partial Solution
1. Which of the following statements are true.
a) Jbir Ibne Hayyan was the author book Kitab Al- Manazir.
False
b) Abyl Qasim Al-Zahravi was a famous Muslim mathematician.
False
c) The speed of light is nearly 300,000 km/sec.
True
d) Ideally water can e used as a car fuel after electrolysis.
True
e) A machine helps us do more work with less force.
True
f) Our eye is very sensitive to blue light.
False
g) We can receive TV sound signal on our FM radio sets.
True
h) Sound can travel through vacuum.
False
i) Famous Muslim botanist Ibn Al Baitar lived during the period 700-90 A.D.
False
j) A ceramic engine would have greater efficiency.
True
2. Fill in the blanks with the correct choice.
a) Al Beruni died in
1048 A.D. (848, 1048, 1248)
b) Abu Ali Sina was born in
Turkey. (Iraq, Turkey, Spain)
c)
Blue colour has shortest wavelength. (blue, yellow, green)
d)
Copper metal has the highest electrical conductivity. (silver, tungsten, copper)
e) light travels fastest in
vacuum. (glass, vacuum, plastics)
f) Our solar system has about
fifty satellites. (thirty-five, fifty, ninety-six)
g) The universe is
expanding. (contracting, expanding, stationary)
h) The disease, haemophiia is caused by the deficiency of vitamin
K (A, K, D)
i)
Protein is a natural polymer. (glucose, protein, polyethylene)
j)
Astronomers cannot be nominated for the Nobel Prize. (physicists, economists, astronomers)
3. Define any five of the following terms.
a) Biogas
b) Geothermal energy
c) Vaccine
d) Antibiotic
e) Ceramics
f) Light year
Answers:
a) Biogas:
Biogas is the result of the controlled microbial breakdown of organic materials such as animal manures or food scraps in an anaerobic digester.Biogas is a mixture of about 60-70% methane (natural gas), 30-40% carbon dioxide and other trace gases, such as hydrogen sulfide.
b) Geothermal energy:
The word geothermal comes from the Greek words geo (earth) and therme (heat). So, geothermal energy is heat from within the earth. We can use the steam and hot water produced inside the earth to heat buildings or generate electricity. Geothermal energy is a renewable energy source because the water is replenished by rainfall and the heat is continuously produced inside the earth.
c) Vaccine:
Vaccine is an immunogen consisting of a suspension of weakened or dead pathogenic cells injected in order to stimulate the production of antibodies.
d) Antibiotic:
Chemical substance formed as a metabolic by-product in bacteria or fungi and used to treat bacterial infections. Antibiotics can be produced naturally, using microorganisms, or synthetically.
e) Ceramics:
Ceramics are classified as inorganic and nonmetallic materials that are essential to our daily lifestyle. This category of materials includes things like tile, bricks, plates, glass, and toilets.Ceramics are generally made by taking mixtures of clay, earthen elements, powders, and water and shaping them into desired forms. Once the ceramic has been shaped, it is fired in a high temperature oven known as a kiln. Often, ceramics are covered in decorative, waterproof, paint-like substances known as glazes.
f) Light year:
A light-year is a unit of distance. It is the distance that light can travel in one year. Light moves at a velocity of about 300,000 (km) each second. So in one year, it can travel about 10 trillion km. More precisely, one light-year is equal to 9,500,000,000,000 kilometers.
5. What are Endocrine Glands? Name any two. From which part of the body are the following secreted:
a) Insulin
b) Thyroxin
c) Adrenaline
d) Oestrogen
e) Testosterone
f) Cortisol
Answers:
“These are those glands which pour their secretions directly into the blood stream”. Their secretions are called as “Hormones” which are the chemical substances produced by the cells of one part and transported by the body fluids to another site of body where they exert their action. They serve as chemical messengers or regulators.
They control growth, metabolism, reproduction and many other functions of body and mind. E.g. Pituitary Gland, Thyroid Gland etc.
The following hormones are secreted by:
Name of Hormone………..Gland secreting Hormone
a) Insulin
…….............…Pancreas
b) Thyroxin
……............Thyroid
c) Adrenaline
…............Adrenal Medulla
d) Oestrogen
…..........…Ovaries
e) Testosterone
…........Testes
f) Cortisol
………............Adrenal Cortex
8. What do the following scientific abbreviations stand for?
a) LPG Liquefied Petroleum Gas
b) TNT Tri niotro toline
c ) RNA Ribonucleic Acid
d) CNG Compressed Natural Gas
e) ATP Adenosine tri Phosphate
f) RBC Red Blood Cells
g) ECG Electro Cardio Gram
h) PVC Poly Vinyl Chloride
i) RAM Random Access Memory
j) CFC Chlorofluorocarbons
9. Write short notes on any two of the following:
a) Acid rain
b) Green house effect
c) Ozone depletion
Answers:
a) Acid rain:
The problem begins with the production of sulfur dioxide and nitrogen oxides from the burning of fossil fuels, such as coal, natural gas, and oil, and from certain kinds of manufacturing. Sulfur dioxide and nitrogen oxides react with water and other chemicals in the air to form sulfuric acid, nitric acid, and other pollutants. These acid pollutants reach high into the atmosphere, travel with the wind for hundreds of miles, and eventually return to the ground by way of rain, snow, or fog, and as invisible “dry” forms.
Acid rain leaches nutrients from soils, slows the growth of trees, and makes lakes uninhabitable for fish and other wildlife. In cities, acid pollutants corrode almost everything they touch, accelerating natural wear and tear on structures such as buildings and statues. Acids combine with other chemicals to form urban smog, which attacks the lungs, causing illness and premature deaths
b) Green house effect:
Greenhouse Effect, the capacity of certain gases in the atmosphere to trap heat emitted from Earth’s surface, thereby insulating and warming the planet. Without the thermal blanketing of the natural greenhouse effect, Earth’s climate would be about 33°C (about 59°F) cooler—too cold for most living organisms to survive.
The greenhouse effect results from the interaction between sunlight and the layer of greenhouse gases in the atmosphere that extends up to 100 km (60 mi) above Earth’s surface. Sunlight is composed of a range of radiant energies known as the solar spectrum, which includes visible light, infrared light, gamma rays, X rays, and ultraviolet light. When the Sun’s radiation reaches Earth’s atmosphere, some 25 percent of the energy is reflected back into space by clouds and other atmospheric particles. About 20 percent is absorbed in the atmosphere. For instance, gas molecules in the uppermost layers of the atmosphere absorb the Sun’s gamma rays and X rays. The Sun’s ultraviolet radiation is absorbed by the ozone layer, located 19 to 48 km (12 to 30 mi) above Earth’s surface.
About 50 percent of the Sun’s energy, largely in the form of visible light, passes through the atmosphere to reach Earth’s surface. Soils, plants, and oceans on Earth’s surface absorb about 85 percent of this heat energy, while the rest is reflected back into the atmosphere—most effectively by reflective surfaces such as snow, ice, and sandy deserts. In addition, some of the Sun’s radiation that is absorbed by Earth’s surface becomes heat energy in the form of long-wave infrared radiation, and this energy is released back into the atmosphere.
Certain gases in the atmosphere, including water vapor, carbon dioxide, methane, and nitrous oxide, absorb this infrared radiant heat, temporarily preventing it from dispersing into space. As these atmospheric gases warm, they in turn emit infrared radiation in all directions. Some of this heat returns back to Earth to further warm the surface in what is known as the greenhouse effect, and some of this heat is eventually released to space. This heat transfer creates equilibrium between the total amount of heat that reaches Earth from the Sun and the amount of heat that Earth radiates out into space. This equilibrium or energy balance—the exchange of energy between Earth’s surface, atmosphere, and space—is important to maintain a climate that can support a wide variety of life.
The heat-trapping gases in the atmosphere behave like the glass of a greenhouse. They let much of the Sun’s rays in, but keep most of that heat from directly escaping. Because of this, they are called greenhouse gases. Without these gases, heat energy absorbed and reflected from Earth’s surface would easily radiate back out to space, leaving the planet with an inhospitable temperature close to –19°C (2°F), instead of the present average surface temperature of 15°C (59°F).
c) Ozone depletion:
Ozone Layer, a region of the atmosphere from 19 to 48 km (12 to 30 mi) above Earth's surface. Ozone concentrations of up to 10 parts per million occur in the ozone layer. The ozone forms there by the action of sunlight on oxygen. This action has been taking place for many millions of years, but naturally occurring nitrogen compounds in the atmosphere apparently have kept the ozone concentration at a fairly stable level.
The ozone layer of the atmosphere protects life on Earth by absorbing harmful ultraviolet radiation from the Sun. If all the ultraviolet radiation given off by the Sun were allowed to reach the surface of Earth, most of the life on Earth’s surface would probably be destroyed. Short wavelengths of ultraviolet radiation, such as UV-A, B, and C, are damaging to the cell structure of living organisms. Fortunately, the ozone layer absorbs almost all of the short-wavelength ultraviolet radiation and much of the long-wavelength ultraviolet radiation given off by the Sun.
In the 1970s scientists became concerned when they discovered that chemicals called chlorofluorocarbons, or CFCs (see Fluorine)—long used as refrigerants and as aerosol spray propellants—posed a possible threat to the ozone layer. Released into the atmosphere, these chlorine-containing chemicals rise into the upper stratosphere and are broken down by sunlight, whereupon the chlorine reacts with and destroys ozone molecules—up to 100,000 per CFC molecule. The use of CFCs in aerosols has been banned in the United States and elsewhere. Other chemicals, such as bromine halocarbons, as well as nitrous oxides from fertilizers, may also attack the ozone layer. Thinning of the ozone layer is predicted to cause increases in skin cancer and cataracts, damage to certain crops and to plankton and the marine food web, and an increase in atmospheric carbon dioxide (Global Warming) due to the decrease in plants and plankton.
10. What are the three components of the CPU in a computer? What is the function of each?
Answer:
Abbreviation for central processing unit, and pronounced as separate letters. The CPU is the brains of the computer. Sometimes referred to simply as the central processor,but more commonly called processor, the CPU is where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system.
it has 3 parts
1)Memory unit: It stores vital information.such as computer language codes.It has 2 parts.
a)Ramdom access memory
b)read only memory
2)The arithmetic logic unit (ALU), which performs arithmetic and logical operations.
3)The control unit (CU), which extracts instructions from memory and decodes and executes them, calling on the ALU when necessary.
12. Briefly describe the principle and function of a camera. Mention its essential parts along with brief comparison with an eye.
Answer:
The most important tool of photography is the camera itself. Basically, a camera is a lighttight box with a lens on one side and light-sensitive film on the other.
Parts:
1.camera box
2.film
3.aperture or diaphragm and shutter
4.the lense
5.the viewing system
Cameras may work with the light of the visible spectrum or with other portions of the electromagnetic spectrum. A camera generally consists of an enclosed hollow with an opening (aperture) at one end for light to enter, and a recording or viewing surface for capturing the light at the other end. A majority of cameras have a lens positioned in front of the camera's opening to gather the incoming light and focus all or part of the image on the recording surface. The diameter of the aperture is often controlled by a diaphragm mechanism, but some cameras have a fixed-size aperture.
Refraction is the phenomenon which makes image formation possible by the eye as well as by cameras and other systems of lenses.
Human eyes have often been compared to cameras. They are alike in terms of structure, but they have one fundamental difference in functioning mechanism.
Table: Similarities & the Difference between Camera and Human Eye
Function Camera Human Eye
Similarities:
1. opening for light to enter aperture in Camera and pupil in eye.
2. control the amount of light entering camera/eye.
diaphragm control size of aperture in camera and iris muscles control size of pupil in eye.
3. refract light glass biconvex lens in Camera .And mainly cornea ; lens, aqueous & vitreous humor in eye.
4. object of light action to form image photosensitive chemicals on film in camera and photoreceptors(rods & cones) in retina of eye.
5. absorb excessive light to prevent multiple images formation dark internal surface in camera and pigmented, dark choroid in eye.
Difference:
1. focusing mechanism change distance between lens & film in camera and change focal length of lens using ciliary muscles in eye.
14. Differentiate between any five of the following:
a) Thermoplastics and thermosetting plastics
b) Lunar eclipse and solar eclipse
c) Asteroid and meteorite
d) Renewable and non-renewable energy resources
e) Endothermic and exothermic reactions
f) Star and planet
g) Nuclear fission and nuclear fusion
Answers:
a) Thermoplastics and thermosetting plastics:
Thermoplastics:
Thermoplastics can be repeatedly softened by heating and hardened by cooling.Thermoplastic molecules, which are linear or slightly branched, do not chemically bond with each other when heated. Instead, thermoplastic chains are held together by weak van der Waal forces (weak attractions between the molecules) that cause the long molecular chains to clump together like piles of entangled spaghetti. Thermoplastics can be heated and cooled, and consequently softened and hardened, repeatedly, like candle wax. For this reason, thermoplastics can be remolded and reused almost indefinitely.
in few words you can say:
1.Thermoplastics can be repeatedly softened by heating and hardened by cooling.
2.Thermoplastic molecules do not chemically bond with each other when heated.
3.examples are Polystyrene and polyethylene .
Thermosetting Plastics:
Thermosetting plastics, on the other hand, harden permanently after being heated once.Thermosetting plastics consist of chain molecules that chemically bond, or cross-link, with each other when heated. When thermosetting plastics cross-link, the molecules create a permanent, three-dimensional network that can be considered one giant molecule. Once cured, thermosetting plastics cannot be remelted, in the same way that cured concrete cannot be reset. Consequently, thermosetting plastics are often used to make heat-resistant products, because these plastics can be heated to temperatures of 260° C (500° F) without melting.
In few words we can say:
1. Harden permanently after being heated once.
2. Molecules that chemically bond when heated.
3. Examples are polyurethane and phenolic.
b) Lunar eclipse and solar eclipse:
A lunar eclipse occurs when Earth is between the Sun and the Moon, and Earth’s shadow darkens the Moon.
A solar eclipse occurs when the Moon is between the Sun and Earth, and the Sun’s shadow moves across the face of Earth. An eclipse is called a total eclipse if the light is completely blocked or a partial eclipse if the light is only partly blocked.
c) Asteroid and meteorite:
Asteroid, small rocky or metallic body that orbits the Sun. Hundreds of thousands of asteroids exist in the solar system. Asteroids range in size from a few meters to over 500 km (300 mi) wide. They are generally irregular in shape and often have surfaces covered with craters
Meteorite, meteor that reaches the surface of Earth or of another planet before it is entirely consumed by heat and friction from the atmosphere. Meteors and meteorites originate as meteoroids in space. On Earth most meteoroids burn up as meteors before they can become meteorites. Meteoroids also strike bodies in space that lack atmospheres, such as the Moon and asteroids, becoming meteorites without being meteors.
Meteor, bright streak of light caused when a small solid body from outer space known as a meteoroid enters the atmosphere of Earth or another planet and is heated by friction from rapid motion through the air. The outer surface of the meteoroid melts and forms an envelope of extremely hot gas and air that radiates light. The meteoroid may burn up almost completely and fall as dust, or it may fragment or explode in midair. Remains of meteoroids that reach the surface are called meteorites.
d) Renewable and non-renewable energy resources:
Renewable energy resources:
Generally a form or forms of energy that are not based on fossil fuels but are renewable sources.they are mostly environmental friendly. Examples, Geothermal Energy; Solar Energy; Tidal Energy; and Wind Energy.
Non-renewable energy resources:
Generally a form or forms of energy that are based on fossil fuels .they are not environmental friendly.
examples, natural gas, oil, wood.patrol etc.
e) Endothermic and exothermic reactions:
Chemical reactions can occur spontaneously if the reactants possess more potential energy (stored energy) than the products. This type of reaction occurs spontaneously because of the downhill energy path (from more potential energy to less). These reactions are called exothermic (heat-producing) reactions, because potential energy is converted to heat as the reactions proceed. Conversely, endothermic (heat-absorbing) reactions do not occur spontaneously because of the uphill energy path that exists. The products of endothermic reactions contain more potential energy than the reactants. As a result, energy must be added to trigger an endothermic reaction.
f) Star and planet:
it will be discussed in 2008 papers.
g) Nuclear fission and nuclear fusion:
it will be discussed in 2008 papers.
15. Fill in the blanks:
a)
Enzymes are biological catalysts which have multiple function in the body.
b) The difference between electrical charges at the two ends of a conductor is called
potential difference.
c) The branch of zoology which deals with the study of insects is called
entomology.
d) Electric current is measured by an
ammeter.
e) Dry ice is solid
carbon dioxide.
f) Fuels formed from animal and plant matter that lived thousands of years ago are known as
fossil fuels.
g) Light with larger wavelength than that of the red colour is called
infra red.
h) Penicillin was discovered by
Alexander Fleming.
i) Medulla Oblongata connects the
small brain with the spinal chord.
j) The pH of normal human blood is
7.45-7.35.
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