Q. & A.s ‑‑‑ SCI.
& TECH. – 12
321Q. What is stealth technology?
Stealth principles
Radar cross-section (RCS) reductions
Vehicle shape
Non-metallic airframe
Radar absorbing material
Radar stealth countermeasures and limitations
Low frequency radar
Multiple transmitters
Moore's law
Acoustics
Visibility
Infrared
Reducing radio frequency (RF) emissions
Measuring stealth
Stealth tactics
322Q. What is triskaidekaphobia?
It is the fear of the number 13.
323Q. What is scientology?
 |
The Scientology Symbol
is composed of the letter S that stands for Scientology and the ARC and KRC
triangles, two important concepts in Scientology
|
Scientology is a body of beliefs and related practices created by L. Ron Hubbard (1911–1986), starting in 1952, as a successor to his earlier self-help system, Dianetics.
Scientology teaches that people are
immortal spiritual beings who have forgotten their true nature.
Scientology is legally recognized as a
tax-exempt religion in the United States and some other countries, and the
Church of Scientology emphasizes this as proof that it is a bona fide religion.
324Q. What is cracking?
It
is an important process in the refining of petrol and other fuels. Crude oils
broken down into different products by a process called fractional
distillation. The oil is heated to a very high temperature and different
products.. cracking breaks down the large hydrocarbon molecules into smaller
molecules and this greatly increases the quantity of products.
Thermal
cracking and catalytic cracking.
325Q. What is centrifuge?
It is a machine used to spin substances
at a high speed.
Blood and other biological
samples are often separated by centrifuge
The fastest centrifuges called
ultracentrifuges spin at up to 2,00,000 revolution per minute.
Large centrifuges are used to
test military pilots and astronauts who have to be able to withstand high
accelerations.
326Q. How are there rings of saturn?
One assumption was that there was
a planet which was between Saturn and jupitor. It broke into millions of
pieces. Those pieces have been rotating around Saturn causing rings.
327Q. What are the effects of UV radiation?
The increased UV radiation could
have been due to atmospheric changes brought about by a number of causes like
volcanism.
UV many also be cause of
overactivity in the sun itself.
The extinction of dinosaurs were
due to UV radition which made it unable to adapt.
328. How do they chill the contents inside a fridge?
Take a small quantity of petrol
in your hand and expose it to the atmosphere. The petrol evaporates leaving a
cooling sensation. This is becuses te petrol has takenthe heat from the hand
and transformed it into vapour. The working substance in the refrigerator is
called refrigerant.
The liquid is then allowed to
expand at a low pressure. During this process it absorbs heat from the space inside the refridgerator
and become a vapour.
The above cycle is repeated in
vapour-compression refrideration wich
differes fundamentally from vapour absorption system.
329Q. What are the Elements of particles of nature?
|
Leptons |
||||||
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Particle
|
Symbol
|
Mass (MeV/c2)
|
Electric Charge
|
|||
|
electron
|
e-
|
0.511
|
−1
|
|||
|
muon
|
μ-
|
105.7
|
−1
|
|||
|
tau
|
τ
|
1784.1
|
−1
|
|||
|
electron
neutrino
|
νe
|
<7.3×10−6
|
0
|
|||
|
muon
neutrino
|
νμ
|
<0.27
|
0
|
|||
|
tau
neutrino
|
ντ
|
<35
|
0
|
|||
|
330Q. What are the Elements of particles of nature?
Gauge Bosons |
||||||
|
photon
|
&ggr;
|
0
|
0
|
|||
|
gluon
|
g
|
0
|
0
|
|||
|
W-boson
|
W
|
80,200
|
1
|
|||
|
Z-boson
|
Z
|
91,170
|
0
|
|||
|
331Q. What are the Elements of particles of nature?
Some Sample Hadrons |
||||||
|
Particle
|
Symbol
|
Mass (MeV/c2)
|
Electric Charge
|
Quark Content
|
||
|
positive
pion
|
π+
|
139.6
|
1
|
ū
|
||
|
positive
kaon
|
K+
|
493.7
|
1
|
ū
|
||
|
proton
|
p
|
938.3
|
1
|
uud
|
||
|
neutron
|
n
|
939.6
|
0
|
udd
|
||
|
lambda
|
&Lgr;
|
1115.6
|
0
|
uds
|
||
For
each of these particles, except the photon, gluon, and Z-boson, there is an
antiparticle with the same mass and opposite charge. In most cases the
antiparticle is denoted by an overbar over the particle symbol (e.g., the
symbol for the antiproton is ̄.
1 Because quarks cannot be
isolated, the masses given for them are approximate.
332Q. What causes blood sugar in diabetic patients initiated?
There are many reasons for this.
1] Experienced people used to say that during child hood days
because of no food, the appetite comes to ground zero. Digestion power also
decreases. After earning millions of rupees earning heavy food becomes very
impossible, The body cannot allow. The insulin released is not enough to excess
food consumed. This may lead to diabetes.
2] The insulin secretion from the bea cells is less in pancreas. If
the upper limit of glucse sustains above 200 mg/dl after 2 hours of post prandial it is suggestiveof diabetes.
3] Ageing is another cause for the initiation of rise of plasma glucose
due to inadequate secretion of insulin.
4] In some cases it is hereditary.
5] In obese persons with high body cannot release insulin.
6] Sedentary workers cannot have body movements. So adequate insulin
cannot be secreted.
7] Virus infections like mumps and cock sackies indirectly effect
the system.
8] Chronic alcoholism.
9] Excessive sweet
10] Excessive consumption of meat
11] Psychological causes such as tension
333Q. What is the Sun
made of?
The Sun is a sphere
of gas. In the Sun scientists have found about 2/3 of the elements that are
known on the Earth. Helium was found there even before it was found on the
Earth. As these elements on the Sun are all light, it is possible that the rest
of the known elements which are heavier can be found nearer the centre of the
Sun.
Yes, but not
uniformly. The Sun is not a solid. It is a sphere of gas. Its rotation is
different. It is faster near the equator of the Sun and slower near its poles.
At its equator, the average rotational period of the Sun is 25 days, and at the
poles it is 34 days.
We may say that the
Sun is all atmosphere, as it is composed of materials in a gaseous state. There
is, however, a definite central sphere of the Sun. This central sphere is
surrounded by two levels of gases. These two levels are called the Sun's
atmosphere.
The central body of the
Sun is the photosphere, or sphere of light. This is the Sun that we see.
Directly above the
photosphere is the chromospheres. The outermost atmosphere of the Sun, above
the chromospheres, is the corona.
The chromospheres is the
first of the two layers of atmosphere that surround the photosphere. Chromospheres
means the sphere of colour. And it is called this because it has a light red colour.
The chromospheres extends for several thousand kilometres above the
photosphere.
339Q. What is a jammer?
It is used in wireless
telegraphy. In order to block a wireless transmission on a frequency, a disturbing
wireless sound is radiated on the same frequency. So the enemy cannot pass the signal to his
friendly station. This is called jamming.
340Q. How to understand
solar energy.
Solar energy is
heat and light, which has the qualities of waves and individual particles
called photons across a vast range of the electromagnetic spectrum.
The sun is a
nuclear furnace, converting hydrogen to helium through nuclear fusion.
The sun releases the energy of
100 billion H-bombs every second.
It's a very
efficient process, converting mass directly to energy through Albert Einstein's
famous equation: E= MC2 where E is energy, M is Mass and C is the
speed of light times itself.
At 186,000 miles
per second light is the fastest speed in the universe.
A tiny bit of mass
can make a vast amount of energy.
341Q Why
do moles form on the human body?
The scientific name of mole is nevus.
The nevi or moles are instructive tumours of the skin. They are mostly 6mm in
diameter.
Thee are numerous clinical and histological types of nevi. The
following g are important ones.
1.
Congenital
nevi :- these are present at birth and are called acquired nevi.
2. Spindle and epitheloid cell nevi:- they are red-pink
nodules and contain large plump cells with pink blue cytoplasm
3. Blue nevi :- these are black blue
nodules and are dendritic with heavily pigmented nevus cells.
4.
Halo
nevi:- these are identical to ordinary
acquired nevi but provided with lymphocytic infiltration surrounding nevus
cells
So they have host immune response.
342Q. why
does a bird not get electrocuted on sitting on a live wire?
As far as a bird sits on a live wire nothing will happen to it. The
bird will be electrocuted only if is other part touches the neutral wire.
343Q. How
are blotting paper and tissue paper different from ordinary paper?
Tissue paper is a thin soft paper. It is almost transparent and
permeable to water etc.
344Q. What
are the electrical losses in India?
There are many losses in power generation in India.
1.
Generation losses
2. Transmission
losses
3. Distribution
losses
4. Mechanical losses
5. Corona
losses in EHV levels
6. Cable
losses
7. Loss
in cooling system
8. Metering
loss
9. Commercial
loss
10. VAR
loading loss
11. Loss
due to breakdown
12. Loss
due to improper maintenance
13. Loss
due to poor earthing
14. Loss
due to over loading
15.
Loss at
consumer points
345Q.
What is 123 agreement?
123 is a clause for agreement in
US’s Hyde Act, and IAEA safeguards.
25
countries of this world have signed on 123
agreement.
Advantages of the member country
1.
Can purchase nuclear reactors
2. Conduct
nuclear tests
3. Build
bombs
4.
Share nuclear knowledge
Disadvantage
1.
Should not oppose US supremacy
2. Surrender
financially to US
3.
Reactors should be bought only from US
