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Every Day Science Paper - 2005
Partial Solution


Part I


1. Write short notes on any TWO of the following: (5 each)

(a) Communication Satellite:


A communications satellite is an artificial satellite stationed in space for the purposes of telecommunications. Modern communications satellites use geosynchronous orbits, Molniya orbits or low Earth orbits. For fixed services, communications satellites provide a technology complementary to that of fiber optic submarine communication cables. For mobile applications, such as communications to ships and planes, for which application of other technologies, such as cable, are impractical or impossible.

(b) Geo-thermal Energy:

The name "geothermal" comes from two Greek words: "geo" means "Earth" and "thermal" means "heat". Geothermal Energy is energy from heat inside the Earth.The centre of the Earth is around 6000 degrees Celsius - hot enough to melt rock. Even a few kilometers down, the temperature can be over 250 degrees Celsius. In general, the temperature rises one degree Celsius for every 36 meters you go down. In volcanic areas, molten rock can be very close to the surface. Geothermal energy has been used for thousands of years in some countries for cooking and heating.

(c) Ultrasonic:

Ultrasound is sound with a frequency greater than the upper limit of human hearing, approximately 20 kilohertz. Some animals, such as dogs, dolphins, and bats, have an upper limit that is greater than that of the human ear and thus can hear ultrasound.

Ultrasound has industrial and medical applications. Medical Sonography (also called ultrasonography) can visualise muscle and soft tissue, making them useful for scanning the organs, and obstetric sonography is commonly used during pregnancy. Typical diagnostic ultrasound scanners operate in the frequency range of 2 to 13 megahertz. More powerful ultrasound sources may be used to generate local heating in biological tissue, with applications in physical therapy and cancer treatment. Focused ultrasound sources may be used to break up kidney stones or for cataract treatment by phacoemulsification.


2. Write short notes on the life and work of the following: (5 each)

(a) AI-Biruni (b) Ibn Al – Haitham


3. Name: (1 each)

(a) The alloy which consists of copper and tin.
Bronze

(b) The device used to measure radioactivity.
Geiger counter

(c) The organ in (the human body which is responsible for the digestion of protein only
Stomach

(d) The instrument used to measure very high temperature.
Pyrometer

(e) The scientist who designed the first internal combustion engine used to burn low grade fuel.
Francois Isaac de Rivaz

(f)The scientist who asserted the earth to be a huge magnet.
William Gilbert

(g) The metal known as quick silver.
Mercury

(h) The device which converts the chemical energy into electrical energy.
Battery

(i) The first person to orbit the earth in space.
Yuri Gagarin

(j) The scientist who discovered water.
Antoine Lavoisier


4-Write briefly about any FIVE of the following: (2each)

(a) Shock Waves

In fluid dynamics, a shock wave is a nonlinear or discontinuous pressure wave. It can also be when the actual molecular or particle speed is moving faster than the wave propagation speed (space shuttle through air). They can and do transport and transmit tremendous amounts of energy (hundreds of Megawatts per square meter for shocks generated by nuclear explosions).

(b) Sound Barrier

In aerodynamics, the sound barrier is the apparent physical boundary stopping large objects from becoming supersonic. The term came into use during World War II when a number of aircraft started to encounter the effects of compressibility, a grab-bag of unrelated aerodynamic effects, and fell out of use in the 1950s when aircraft started to routinely "break" the sound barrier.

(c) Solar Cell

A solar cell, or photovoltaic cell, is a semiconductor device consisting of a large-area p-n junction diode, which, in the presence of sunlight is capable of generating usable electrical energy. This conversion is called the photovoltaic effect. The field of research related to solar cells is known as photovoltaic.

(d) Super Fluid

Super fluidity is a phase of matter characterized by the complete absence of viscosity. Thus super fluids, placed in a closed loop, can flow endlessly without friction. Super fluidity was discovered by Pyotr Leonidovich Kapitsa, John F. Allen, and Don Misener in 1937. The study of super fluidity is called quantum hydrodynamics.

(e) Tsunami

Tsunami is a natural phenomenon consisting of a series of waves generated when water in a lake or the sea is rapidly displaced on a massive scale. Earthquakes, landslides, volcanic eruptions and large meteorite impacts all have the potential to generate a tsunami. The effects of a tsunami can range from unnoticeable to devastating.

(f) Photovoltaic Cell
Same As Solar Cell.

(g) Hygrometer

Hygrometers are instruments used for measuring humidity. The simplest form of a hygrometer consists of two thermometers, one of which has its bulb constantly kept wet. Evaporation from the bulb lowers the temperature so that this thermometer usually shows a lower temperature.

5. Which physical quantities are measured by the following units? (1 each)

(a) Coulomb
Unit of electrical charge

(b) Weber
Unit of magnetic flux

(c) Tesla
Unit of magnetic flux density

(d) Siemen
Unit of conductance

(e) Rutherford
Unit of rate of decay of radioactive material

(f) Faraday
Unit of electric charge

(g) Angstrom
Unit of length, used especially to specify radiation wavelengths

(h) Parsec
Unit of astronomical length

(i) Degree
Unit of measurement of an angle

(j) Steradian
Unit of solid angle measurement

6. How do our domestic and industrial activities pollute water? Explain with reference to two important industries of Pakistan. (5,5)


7- Which of the following statements are True and which are False: (1 each)

(a) To stay in the sunlight while circling the globe at the equator, one has to move with a speed of 1670 km/hour.
True

(b) Infrared waves have more wavelengths than the red colour.
True

(c) Liver produces bile which is involved in the breakdown of fats.
True

(d) A secondary cell can be charged again.
True

(e) Nucleic acids are responsible basically for protein synthesis in the human body,
True

(f) The quality of gasoline is checked by its octane number.
True

(g) Image in a plane mirror is not laterally inverted.
False

(h) Horse power is the unit of mechanical energy.
False

(i) Sound travels faster in vacuum than in water.
True

(j) Nitrogen is the most occurring element in the human body.
False


8. Differentiate between the following pairs. (2 each)

(a) Radiotherapy & Chemotherapy

Radiotherapy:

Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancer treatment to control malignant cells. Radiotherapy may be used for curative or adjuvant cancer treatment. It is often used as a palliative treatment, where cure is not possible and the aim is for local disease control or symptomatic relief.

Chemotherapy:

Chemotherapy is the use of chemical substances to treat disease. In its modern-day use, it refers almost exclusively to cytostatic drugs used to treat cancer.
In its non-oncological use, the term may also refer to antibiotics (antibacterial chemotherapy).

(b) Penumbra & Umbra

Penumbra:

The penumbra (Latin for mid-shadow) is the portion of a shadow that results from the source of illumination being only partially blocked. Penumbras only occur when the source of light is not a point-source. As the sun is a visible disc, solar shadows have penumbras. The penumbra part of a shadow is contrasted with the umbra part of the shadow in which the light source is completely blocked.

Umbra:

The umbra (Latin for shadow) is the darkest part of a shadow. From within the umbra, the source of light is completely blocked by the object causing the shadow. This contrasts with the penumbra where the light source is only partially blocked and there is only a partial shadow.
The umbra is also the comparatively dark central region of a sunspot.

(c) Springtides & Neaptides

Neap Tides

When the moon is at first quarter or last quarter, it’s located at right angles to the sun. Then the gravity of the sun and moon pull at cross-purposes, and the range between high and low tides is at its least. These are neap tides, and at such times the difference between high and low tides might be only inches a day.

Spring tides

But whenever there’s a full moon or a new moon, the Earth, sun and moon make a straight line – more or less – in space. Then the sun and moon’s gravity combine to create extremely high and low tides, known as spring tides.

(d) Vertebrates &. Invertebrates

Vertebrates:

Living Beings which do have spinal columns or backbone are said to be vertebrates. The internal skeleton which defines vertebrates consists of cartilage or bone, or in some cases both. The skeleton provides support to the organism during the period of growth. For this reason vertebrates can achieve larger sizes than invertebrates.

Invertebrate:

Invertebrate is a term to describe any animal without a spinal column. It therefore includes all animals except vertebrates.

(e) Fluorescent light & Neon signs

Florescent Light:

The common fluorescent tube relies on fluorescence. Inside the glass tube is a partial vacuum and a small amount of mercury. An electric discharge in the tube causes the mercury atoms to emit light. The emitted light is in the ultraviolet range and is invisible, and also harmful to living organisms, so the tube is lined with a coating of a fluorescent material, called the phosphor, which absorbs the UV and re-emits visible light.

Neon Signs:

Neon signs are produced by the craft of bending glass tubing into shapes. A worker skilled in this craft is known as a glass bender, neon or tube bender.
The neon sign is an evolution of the earlier Geissler tube (also called a Crookes tube), which is a glass tube for demonstrating the principles of electrical discharge.


9. Fill in the blanks: (1 each) '

a)The variation in the blood flow can be heard with an instrument called stethoscope.

b)There is a place in the retina where the light sensitive cells are interrupted by the presence of the optic nerve head. It is known as Blind Spot.

(c) The study of human population is called Demography.

(d) Human beings belong to species called mammals.

(e) Defect of eye due to which nearly located objects arc not clearly visible is called Farsightedness also called Hypermetropia

(f) About 65% of the human body consists of water.

(g) All of the oxygen that you breathe has been produced by the splitting of water during Photosynthesis.

(h) The important ore of Chromium is Chromite.

(i) Nitric acid was discovered by Jabbar bin Hayyan.(HCL was also discovered by him)

(j) The measurement of rainfall is made by an instrument known as rain gauge.

10. What are the main reasons of water - logging in Pakistan? How does a tube-well reclaim a water logged soil? (5,5)


Part II


11 . Give scientific reason of the following: (2 each)


(1) Pole star is always seen in the north.

Because the pole star, which we have in the south, is too faint that it cannot be seen from the naked eye.

or

Because the earths motion is from east to west and not from south to north, around its own axis.

(2) We never see birds urinating.

They don’t have urethra in their body, by which normally mammals urinate.

(3) Pasteurized milk has more nourishment than the ordinary boiled milk.

Because its normally refrigerated, covered and protected. It is heated for a very short time, which not only kills the microbes but also prevents the delicate proteins and vitamins to loose.

(4) Bees die when they sting human beings.

Their stingers are actually ovipositors, tubular structures extending from the abdomen that sometimes contain eggs. When the barbed stinger is left inside the victim, the honeybee mortally tears her abdomen in the process. They leave their stingers in the wound with a tiny venom sac attached. Fortunately, only about one out of a hundred people are allergic to bee stings, but allergic reactions can be very serious.

(5) Cloudy nights are usually warmer than the clear ones.

Clouds will insolate the lower troposphere, causing the temperature to not cool off as much at night. The clouds form an attic over and entraps the air. This prevents to the heat to get lost in the atmosphere, above the clouds. Ultimately, the heat produced in the vicinity is restored.

12. What are Nuclear reactors?

A nuclear reactor is a device in which nuclear chain reactions are initiated, controlled, and sustained at a steady rate. Nuclear reactors are used for many purposes, but the most significant current uses are for the generation of electrical power and, in rare cases, for the production of plutonium for use in nuclear weapons.

--How the Electrical energy is produced by Nuclear Power Plants?

A nuclear power plant (NPP) is a thermal power station in which the heat source is one or more nuclear reactors generating nuclear power.

Nuclear power plants are base load stations, which work best when the power output is constant (although boiling water reactors can come down to half power at night). Their units range in power from about 40 MWe to almost 2000 MWe, typical of new units under construction in 2005 being in the range 600-1200 MWe.

As of 2005 there are 441 nuclear power reactors in operation around the world, which together produce about one-sixth of the world's electric power.


--Name the devices which convert:

(1) Mechanical energy into electrical energy
Electric Generator/Dynamo

(2) Heat energy into mechanical energy
Combustion Engines

(3) Electrical energy into mechanical energy
Electrical Motors

(4) Electrical energy into sound energy
Speakers

(5) Sound energy into electrical energy
Microphone

13. What do the following scientific abbreviations stand for: (1 each)

(a) I-1DL

(b) McV - Means Cell Volume

(c)UHF - Ultrahigh Frequency

(d) LED - Light-Emitting Diode

(e) LCD - Liquid Crystal Display

(f) BASIC - Beginner's All-Purpose Symbolic Instruction Code

(g) MASER - Microwave Amplification by Stimulated Emission of Radiation

(h) ETT - Educational Telecommunications and Technology

(i) HST - High-Speed Train or Hubble space telescope

(j) DBSDirect Broadcast Satellite or Direct Broadcasting by Satellite.

14-Compare the columns A and B and write the correct answer from the Column to the Column A (serial wise) in Column C,

Column A-------- Column B ------Column C


1. Gunpowder----Sulphur dioxide -- Sulphur Dioxide
2. Marble--------Fermi ----------- Calcium Carbonate
3. Ozone ------- Aqua regia----- - Dobson Unit
4. Argon --------Beta- Particle ----Blue purple light
5. Quartz -------Frequency -------Silicon Dioxide
6. Mirage -------Calcium Carbonate -Total Internal Reflection
7. Gold ---------Dobson Units----- -Aqua Regia
8. Modulation ---Silicon dioxide -----Frequency
9. Length -------Total internal reflection -Fermi
10. Solar Energy--Blue purple light ---Beta Particle

15. Choose the best choice in the following statements.

(I) Select the correct association :

(a) Oxidation-Loss of an electron
(b) Oxidation - gain of an electron
(c) Reduction - gain of a neutron
(d) Reduction - loss of a neutron

(2) Radioactive isotope of Uranium used in Nuclear Bomb is:

(a)92 U 235
(b)92 U 234
c)92 U 233
d)92 U 238

(3) Human population growth is greatest in developing countries because:

(a) the birth rate is high in developing countries
(b) the death rate is high in developing countries.
(c) much of the population has already reached the child bearing age.
(d) most of the world's population lives in industrialized countries.

(4) Which woody raw material is used for the manufacture of paper pulp?

(a) Cotton
(b) Poplar
(c) Bagasse
(d) Rice straw

(5) Rectified spirit contains alcohol about:

(a) 80%
(b) 95%
(c) 70%
(d) 85%

(6) Which of the following elements is not present abundantly in earth's crust:

(a) Silicon
(b) Radium
(c) Aluminum
(d) Carbon

(7) The famous book; Al - Qanoun was written by the Muslim scientist:

(a.) Jabar bin Hayyan
(b) Zakariya Al - Razi
(c) Abu Ali Sina
(d) Abdul Qasim Majreeti

(8) Basic metals can be converted into gold by:

(a) Heating
(b) Beating
(c) Artificial nuclear radioactivity
(d) Chemical reaction

(9) A light year is a unit of:

(a) Time
(b) Energy
(c) Length
(d) Mass

(10) One of the main function of the earth's ozone layer is to:

(a) Prevent global warming
(b) Filter out ultraviolet rays
(c) Absorb pollution
(d) All of the above
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Last edited by Princess Royal; Tuesday, March 23, 2010 at 08:25 PM.
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