1. Write short notes on any two of the following :
a. superconductivity
The pairing of electrons in certain materials when cooled below a critical temperature, causing the material to lose all resistance to electricity flow. Superconductors can carry electric current without any energy losses.
About one third of all metals loose all electrical resistance at temperatures below a specific critical temperature. Many elemental metals are superconductors. Some critical temperatures are: lead Tc = 7.2 K, tin Tc = 3.7 K, niobium Tc = 9.2 K, aluminum Tc = 1.2 K, mercury Tc = 4.2 K, and vanadium Tc = 5.3 K. Compounds can have even higher critical temperatures. YBa2Cu3O7 has a critical temperature of Tc = 92 K and HgBa2Ca2Cu3O8 has a critical temperature of Tc = 133 K. Superconducting wires can carry currents with zero losses up to very high current densities. Above a critical current density Jc, superconductivity is supressed. A typical critical current density is 106 A/cm2. Superconductivity is also supressed by strong magnetic fields.
b. Night Vision Technology
c. Seismograph
a measuring instrument for detecting and measuring the intensity and direction and duration of movements of the ground (as an earthquake). It senses and records the vibrations that radiate out from the earthquake focus. It is a machine for measuring the intensity of earthquakes by recording the seismic waves that they generate.
2. Briefly write down characteristics of :
a. Mercury
Mercurius = [Latin] messenger god, it is the eighth largest planet in the solar system in terms of size and is nearest to the sun.. The Hubble Space Telescope cannot be turned on Mercury because its orbit causes Mercury to always have too much of the Sun in the frame. That kind of exposure to the Sun would destroy the Hubble.
b. Pluto
The furthest and smallest planet from the Sun , the little planet is only 65% the diameter of Earth’s moon and shows little surface detail. Pluto’s orbit is quite elliptical, it is the most distant planet, but it can come closer to the sun than Neptune.
Because of the erratic nature of Pluto's orbit, some scientists insist that it is an asteroid. Also, Pluto rotates in the opposite direction of most of the other planets. However, Pluto has its own moon, Charon. Pluto's name in Roman mythology was the name of the god of the Underworld.
3. Name :
a. The desert mammal which does not drink water :Knagaroo Rat
b. The mixture which can dissolve platinium : Aqua regia
c. The constituent elements of Bronze : Tin and Copper
d. The vitamin whose deficiency causes a disease called beri beri : Thiamine(B1)
e. The electrical device which transform voltage : transformer
f. A nuclear reaction in which two or more than two lighter nuclear are fused together to form a relatively heavier one : nuclear fusion
g. The purest naturally occurring crystalline form of carbon : diamond
h. The hormone secreted by adrenal cortex : aldosterone
i. The three colours combination which produces the sensation of white light : Red green and blue
j. The defect of vision because of which a person cannot see distant objects clearly : Myopia or Short sightedness
4. What are fertilizers ? what do you understand by the term NPK fertilizer ? How do fertilization contribute to the pollution ?
5. Write briefly about any five of the following
a. Nuclear radiation
Three are atomic nuclei of some elements that continuously emit some ultraviolet waves called radiation. When the process of radiation is stimulated through various nuclear processes it is called nuclear radiation. The important nuclear radiation, from a weapon standpoint, are alpha and beta particles, gamma rays and neutrons. All nuclear radiation is ionizing radiation, but the reverse is not true; X-rays for example, are included among ionizing radiation, but they are not nuclear radiation since they do not originate from atomic nuclei.
5.
b. Theodolite
An instrument used in surveying to measure horizontal and vertical angles with a small telescope that can move in the horizontal and vertical planes.
c. Dialysis
d. Enrichment of Uranium
Uranium is a radioactive element that occurs naturally in the earth's surface. Uranium is used as a fuel for nuclear reactors. Uranium-bearing ores are mined, and the uranium is processed to make reactor fuel.
In nature, uranium atoms exist in several forms called isotopes - primarily uranium-238, or U-238, and uranium-235, or U-235. In a typical sample of natural uranium, most of the mass (99.3%) would consist of atoms of U-238, and a very small portion of the total mass (0.7%) would consist of atoms of U-235.
To enrich the uranium, a process called gaseous diffusion was developed by the United States in the 1940s. The gaseous diffusion process creates two products: enriched uranium hexafluoride, and depleted uranium hexafluoride (depleted UF6).
Enriched uranium is used for the defense needs and in making fuel for commercial light water nuclear power reactors. Depleted UF6 has had only limited uses, and since gaseous diffusion was initiated in the 1940s, large quantities of depleted UF6 has accumulated at the gaseous diffusion plants where it was created.
e. Richter Scale
A scale for measuring the magnitude of an earthquake devised by the American seismologist Charles Richter. The device measures the tremors originates during the earth quake and shows its intensity on scale which is from 1 to 10, ten being the highest while one is the lowest of scales in terms of intensity of earth quake.
f. Aqua regia
Aqua regia is a 3:1 mixture of hydrochloric acid and nitric acid. Aqua regia is used to test gold and platinum; it is just about one of the few substances that can dissolve gold and platinum.
g. Iodized salt
Iodine is a natural element required by the human body for proper physical and mental development. It is essential to the production of hormones that affect many parts of the body, particularly muscles, the heart, liver, kidneys and the brain. While most people receive sufficient amounts of iodine from their daily diets, but number of people cannot get it as their soil lacks iodine and because they lack access to foods which contain iodine.
Physical manifestations of iodine deficiency (IDD) include mental retardation, coordination abnormalities, deaf-mutism, spastic diplegia (spastic paralysis of the lower limbs) and dwarfism. During childhood, mild IDD can result in permanent intellectual impairment, with the intelligence quotient lowered by 10-15 points
To overcome the deficiency, Salt has become the most accepted food for iodine fortification because it is one of the few commodities that is almost universally consumed by all sections of a community, and at approximately the same level throughout the year, irrespective of economic level.
6. Which physical quantitites are measured by the following units ?
a. Rutherford : strength of radioactivity
b. Torr: pressure
c. Fermi : length [A unit of length equal to one femtometer (10-15 meter)]
d. Sved berg unit:sedimentation rate
e. Dioptre: power of lense
f. Mho : conductivity
g. Henry: inductance
h. Maxwell: magnetic flux
i. Becquerel: radioactivity
j. Kilo watt hour: power
7. What are the various sources of energy ? How does energy is produced in the surface of the sun ? what will be the future of the sun ?
8. Which are the following statements true and which are false ?
a. a six feet tall lady can see her full image in a three feet Plane Mirror: T
b. Vanadium, a steel gray corrosion resistant metal occur naturally in oxide state :
c. Fibre optics cable carries data in the form of light: T
d. Blue flame is hotter than red flame : T
e. The falling of yellow leaves during autumn is the seasonal time for plants to get rid of accumulated wastes : T
f. Friction is necessary evil: T
g. There are 9.5 x 1015 m in one light year B
h. The velocity of a moving object is least where the pressure is greatest
i. Heat reaches earth from the sun by means of convection : F
j. Meningitis is the inflammation of liver : F
9. Differentiate between the following pairs
a. periscope & pyrometer
periscope is an optical instrument
pyrometer is a meter used to measure high temperature
b. cell & battery
Cell is a small unit/device that delivers an electric current as the result of a chemical reaction
Battery is a device that produces electricity having several cells arranged in parallel or series
c. perimeter & altimeter
the area around the polygon is perimeter and altimeter is the device used for measuring the altitude of some place
d. pelage and plumage
pelage is growth of hair/fur/wool covering the skin of animals while plumage are feathers covering the body of birds
e. smog and smoke
Smog is formed by the interaction of pollutants present in the air in presence of sun light (photochemical smog), it usually restricts visibility and is hazardous to health
Smoke are the thin fine particles usually result from the combustion
10. fill in the blanks
a. the largest planet of solar system is _____ (Jupiter)
b. the temperature of the dead human body on Celsius scale is ___
c. for a large span of a long jump, two things are taken into account viz i angle with which one jumps and ii ____ (speed/angle of projection)
d. the number of the spinal nerves in the man is ____ pairs (31)
e. a primary cell can ___ be charged again (not)
f. Halos around the moon are formed because of the phenomenon of ___ (optical phenomena)
g. Scattering of light ___ the duration of the day (make)
h. Muscle stiffness is caused by a disease called ___ (Parkinsons)
i. Oil rises in a wick of oil lamp on account of a property of matter called ___
j. Muslim scientist Ali al Tabari is famous for his work on ___ (medical sciences)
11. Give scientific reason of the following
1. rain water is more fertile than water from tube well
after falling, the rain drops start moving on slope side, during this movements, the soluble salts and minerals solves from top soil in the flowing water, which increases its fertility, while the rain drops which percolates into deeper regions of soil are note able to absorb more salts and minerals so is less fertile as compared to rain water in streams
2. the man-hole covers are generally round
Manhole covers are round so that is doesn’t get dropped accidentally into the manhole. The round shape requires less space than a square and makes handling easier. Once removed, the cover can be transported by rolling.
3. clothes of a moving dancer bulge
due to movement of dancer the clothes got electric charge, which on fast movement collides with the opposite charge so the clothe bulge inside out
4. peoples are advised not to stand near a fast moving train
people are advised not to stand near a fast moving train as the train in tremendous speed cuts the pressure of air which can disbalance the objects after passing of train present near the railway line
5. the image of a tree looks inverted on the bank of a lake
12. why are the scientists worried about the increase of carbon dioxide gas in the atmposphere ? is there any possible benefit for the mankind in case of global warming ?
13. what do the following scientific abbreviations stand for ?
a. STP standard temperature and pressure/ Shielded Twisted Pair
b. ATP Adenosine Tri-Phosphate
c. PNP proton – neutron – proton
[Positive-Negative-Positive (transistor) ]
d. LAN local area network
e. KWh kilo watt hour
f. BTU British Thermal Unit
g. LDL Low-density lipoprotein
[commonly referred to as bad cholesterol]
h. ROM Read only memory
i. MAF million acre feet
j. SONAR Sound Navigation and Ranging
14. Match the column A and B but write the answers serial wise in column C
S.No. Column A Column B Column C
A Frank whittle Fission C
B Addison Electricity B
C Hahn Genetics D
D Mendel Lightening conductor E
E Benjamin Franklin Semi conductor F
F Bardeen & Brattin Uncertaininty principle G
G Heisenberg Jet engine A
H Fermi Cyclotron I
I Lawrence Electro magnetic waves J
J Maxwell Hertz Fusion
Length H
Steam Engine
15. Choose the best choice in the following statements
1. the three elements needed for healthy growth of plants are :
a. N, P, K b. N, C, P c N, K, C d N, S, P
A
2. the most abundant element in the human body is :
a. Carbon b. Hydrogen c. Oxygen d. Nitrogen
C
3. ammonium nitrate is not used for :
a. Rice crop b. wheat crop c. sugarcane crop d. cotton crop
4. sea divers use a mixture of gases for breathing during diving. The mixture is :
a. 80% He & 20%O2 b. 80% N2 & 20 O2 c. 20%O2 & 40% N2 40% CO2 d. 50% He & 50% O2
B
5. Which one of the following is a water soluble vitamin
a. Niacin b. Ascorbic acid c. trypsin d. riboflavin
B
6. Which of the following enzymes bring about hydrolysis of fats ?
a. urease b. zymase c. maltase d. lipase
D
7. the solution of which acid is used for seasoning of food :
a. formic acid b. acetic acid c. benzoic acid d. botanic acid
D
8. influenza is caused by :
a. fungi b. bacteria c. virus d. protoza
C
9. the blood glucose level is raised by the following except :
a. carbohydrates b. cholesterol c. insulin d. epinephrine
C
10. the energy possessed by water in a dam is :
a. electrical energy b. kinetic energy c. potential energy d. mechanical energy
C
