GENERAL SCIENCE BIT BANK
The removal of water from the plants in the
form of liquid droplets is called Guttation.
Headquarters
of the World Meteorological Organisation is located at Geneva.
The native
place of groundnut is Brazil.
Kisan Day is
celebrated on 23rd December.
Central
institute of Sub-tropical Horticulture is located at Lucknow.
National
Research Centre of Agro-forestry is located at Jhansi.
Blue green algae are used
to supply nitrogen to paddy.
1st
dwarf rice variety developed in India was IR-8.
‘Dapog’ method of
rice nursery was developed in Philippines.
Pink revolution is related to Onion.
White tip of maize leaves indicates the deficiency of
Zinc.
As
per the WHO the safe noise level for a city is 45db.
Loss of memory is caused by the destruction of
Cerebellum.
The
main constituent gas of LPG is Butane.
The
direction of vibration of particles with respect to wave direction in transverse
wave is Right angle.
X-Ray is Electromagnetic wave.
Yellow spot occurs in Eye.
Mach number is the ratio of Velocity of sound and
velocity of a body.
Bile is produced by Liver.
At
40 C, volume of a certain mass of water is minimum.
The
source of hydrogen for carbon assimilation is NADPH2.
Many
elements have non-integral atomic masses because their isotopes have
non-integral masses.
Newton’s
laws of motion are valid in Inertial frame of reference.
Light
refractive index of glass in minimum for Red colour.
Red blood corpuscles have life of 4 months.
Concentrated HNO3 can be stored in container
made up of Al.
If
mass is increased by 2 times and velocity is increased by 3 times
of a body then its momentum will be increased by 6 times.
Effect of increasing temperature on resistance
of semiconductor is decreasing.
Apart
from quinine, the herbal drug Arteether is also used to cure malaria.
‘Chilgoza’
is obtained from the seeds of a species of Pine.
One
kilowatt-hour equals to 3.6 x 106 J.
The
atoms, in which the number of protons is same but the number of neutrons is
different, are known as Isotopes.
A
fluorescent tube is preferred to an electric bulb because in a tube
electrical energy is almost fully converted into light.
Vinegar
is an aqueous solution of Acetic acid.
A
jet engine uses the surrounding air for its oxygen supply and so is
unsuitable for motion in space.
A
rocket carries its own supply of oxygen in the gas form as fuel.
Enriched Uranium is Natural Uranium in which
the component of radio active isotope U235 is artificially
increased.
Semiconductor laser is used in a laser printer.
The
inexhaustible source of energy of the stars is due to Conversion of
Hydrogen to Helium.
The
leaning tower of Pisa does not fall because the vertical line through
the centre of gravity of the tower falls within the base.
One barrel of oil is equal to 158.6 liters (159 liters).
While lifting a bucket of water from a
well, we feel that the bucket becomes heavier above the surface of water.
Nutraceuticals are products having Nutritional
and medicinal effects.
The
thermometer suitable to measure 20000 C is Total radiation
Pyrometer.
A
colour-blind man marries a normal woman. The features of colour
blindness will appear in his Daughter’s Sons.
When
soggy biscuits are kept inside the fridge for sometime they become
crisp because Humidity inside the fridge is low and extra moisture is
absorbed.
Marie Curie won her two different Nobel Prizes in the
fields of Physics and Chemistry.
Soft drinks such as Colas contain significant quantities
of Caffeine.
The
glucose level in commonly expressed as Milligram per deciliter.
Most
of the explosions in mines occur due to the mixing of Methane with
Air.
As
per the recently released data the warmest decade in the recorded history of
160 years is 2000-09.
Jonas E Salk in 1955 is credited with discovering anti
polio vaccine.
At
constant temperature if the pressure decreases, the volume of
a given mass of a gas will increase.
The
electromagnetic radiation that is emitted during radioactive disintegration
is Gamma rays.
61.8% of human body is water by weight.
The
walls of a music hall should absorb sound.
The
constituents of compressed Natural Gas (CNG) principally are Methane and
Ethane.
Strontium and Barium salts provide colors to fire
works.
Aditya is a satellite to study the Sun.
Word lengths for supercomputer range up to 64
bits.
At 1600 F, the Fahrenheit temperature is
double of centigrade temperature.
In
weightlessness condition, the size of flame of a candle will remain
same.
The
minimum distance between the source of sound and reflecting surface
to hear an echo clearly is 17 meters.
Bioremediation means Elimination of toxic
pollutant from environment by organisms.
The
sun is visible to us a few minutes before the actual sunrise
because of Refraction of light.
In
a capillary tube a fluid rises more as compared to water, it is due
to Surface Tension of fluid is less than that of water.
Helium gas is mixed with oxygen for respiration by
divers in deep sea.
Chemically
‘Plaster of Paris’ is Calcium Sulphate.
It
two bubbles of soap of different diameter come in contact by a tube,
then the smaller bubble will become more smaller and bigger will become more
bigger.
The
temperature of the filament of lighted electric bulb is generally
20000 C – 25000 C.
The
names of endangered plants are enlisted in Red Data Book.
Power Pack Project is related with Electrification
with solar energy in the remote rural areas.
Big Bang Theory is related with Origin of
Universe.
Pituitary gland secretes the milk ejection
hormone oxytosine.
The
PH level of blood of a normal person is 7.35 -7.45.
The
release of Gambusia Fish into Ponds and wells helps in controlling
the mosquitoes.
Xenon is called Stranger Gas.
Rubies and Sapphires are chemically known as Aluminum
Oxide.
A
widely used musical scale called diatonic scale has seven frequencies.
Agent Orange is a weed killing chemical used by the US
military in the Vietnam War.
A
light emitting diode, usually called an LED is a semiconductor
diode that emits in coherent narrow spectrum light when electrically biased in
the forward direction on the p-n junction.
Blue LEDs are based on the wide band gap semi conductors
GaN(gallium nitride) and InGaN( Indian Gallium Nitride).
Cobalt-60 is commonly used in radiation therapy,
because it emits Gamma rays.
In
the human body, the longest cell is known Liver Cell.
Nichrome is used to make electric heater coil.
The
formation of fruit without fertilization is known as Parthenicarpy.
Root modules are commonly found in leguminous plants.
ALZHEIMERS disease is a disorder of the brain.
Chromosomes of the father will determine the sex of a
child.
Hypermetropia or long sight can be corrected by using Concave
lenses.
Hypoglycemia refers to low sugar level in blood.
The
antibiotic Ampicillin is a semi synthetic drug.
Opium is a plant product obtained from dried latex.
Drying oils contain a fairly large proportion of unsaturated
fatty acids.
In
mirrors the back surface is coated with a thin layer of Silver.
When
quick lime is added to water, heat is liberated.
H5N1 virus is
contagious for human beings.
Metal present in blood is Iron.
Night photography and photography in mist and fog are
possible using Infra-red radiation.
In
digestion, proteins are converted into Amino Acids.
The
minimum temperature at which a combustible substance catches fire is
called ignition temperature.
Centre for DNA Finger printing is located at Hyderabad.
Cryogenic engines are used in Rockets.
Workers of paint industry are exposed to Lead Industry.
Nitrate is responsible for blue baby syndrome.
Athletes with higher proportion of Red fibers in their
muscles are better equipped for swimming.
Stem cell has the ability to develop into any type of
cell.
The
approximate height of a geostationary satellite from the surface of the
earth is 36,000 Kms.
Skin cancer is caused due to presence of excess Arsenic
in water.
Silk is a protein fiber.
Ganymede is the largest satellite in solar system.
Microwaves have the highest frequency.
All enzymes are proteins but all proteins are not enzymes.
In
electric supply lines in India, Frequency is kept constant.
The
flavour of apples is mainly due to Benzaldehyde.
Freon used as refrigerants is chemically known as
Fluorinated hydrocarbon.
German silver is an alloy of copper, Zinc
& Nickel.
The
tracking of people by trained dogs is based on the recognition of
carboxylic acids in the sweat from feet.
Boiling point of water depends on atmospheric
Pressure.
An
Astronaut in outer space will observe sky as Black.
Cylindrical lenses should be used to correct the
defect of ASTIGMATISM.
Infrared rays have the longest wave length.
Electron was discovered by Joseph Thomson.
The
1st thermionic valve was invented by J.A.Fleming.
A
substance which readily forms colloidal solution in contact with water is
called Hydrophilic colloid.
The
Enzyme in whose presence glucose and fructose are converted into alcohol
is Zymase.
Oxalic acid is manufactured using Sawdust.
The
study of visceral organs is Splanchnology.
The
science dealing with the study of teeth is Odontology.
The
branch of biology dealing with the study of cells is known as Cytology.
The
study of extinct animal is called Paleontology.
The
medical term used for the sleeplessness is Insomnia.
The
causative agent of Tuberculosis is Mycobacterium.
The
enzyme that is present in the saliva of man is Amylase.
Blood cancer is otherwise called as Leukemia.
WLL stands for wireless in Local Loop.
Superconductors
are those elements whose resistance falls almost to Zero at very low
temperatures.
Suppose
if we measure the time lapse between the two sunsets by sitting in the beach,
from this we can estimate the radius of the earth.
Radio
immunoassay (RJA) is a therapy used to detect antibodies and hormones present
in the blood samples.
In
a Laser all the atoms emit the light waves of same frequency, amplitude and
phase.
The
polymer used in making plastic crockery is Melamine.
Vulcanization
of Rubber is carried out by adding Sulphur.
World
Health Day is observed on April 7.
If
the temperature of a place increases suddenly the relative humidity Decreases.
Diphtheria
is caused by bacteria and spreads through faecal matter by houseflies.
In
a living cell, the site of ribosome formation is Endoplasmic reticulum.
Carbon
is the principal structural element of a living cell.
Chloroplast
is considered as a cell with in a cell.
A
kidney carries out the function in human beings similar to the one which
Malpighian tubules perform in cockroaches and other insects.
A
surge of Luteinizing hormone stimulates ovulation in human females.
Mildness
of shaving cream is enriched by Potassium Carbonate.
The
purpose of adding plasticizers in paint manufacturing process is that they
provide elasticity to the film and minimize its cracking.
Graphite
can be used as lubricant because it has low viscosity.
Muriate
of Potash fertilizer is assimilated directly by the plant.
Cylindrical
lens is used to remove astigmatism from human eye.
When
an electric bulb breaks, the reason for a mild bang is due to compressed gases
rush out suddenly.
Specific
gravity remains same in all systems of units.
A
test tube baby means Fertilization in Vitro and then transplantation in the uterus.
Tele
text is flashing of the text of news and information on the TV screen.
The
causative agent of Tuberculosis is Mycobacterium.
An
aeroplane is able to fly because, Moving air can lift objects.
Deficiency
of insulin causes Diabetes.
Boiling
point of water in Fahrenheit scale is 2120 C.
The
instrument used to measure an angle accurately is vernier bevel Protractor.
From
Carbon with Silicon, phosphorus and Sulphur make an alloy of Steel.
The
number of chromosomes present in the somatic cell of the human cell is 46.
Earthworm
has a clitellum.
The
acid which is secreted by the glands in the stomach wall is HCL.
Kidneys
excrete water, fat and various catabolic wastes.
An
optically plane surface reflects a beam of light as a parallel beam in one direction.
Water
is used in car radiator because of its high specific heat capacity.
The
trace metal present in insulin is Zinc.
The
metal present in chlorophyll is Magnesium.
Dry
ice is solid carbondioxide.
Cement
containing excess amount of lime cracks during setting.
The
vessel which carries the venous blood to the lungs for oxygenation is Pulmonary
arteries.
Quinine,
the commonly used drug to treat malaria, is obtained from stem bark of a plant.
Most
of the fish do not sink in water because of the presence of Swim bladder.
Heavy
alcohol consuming people generally die of Cirrhosis.
Chocolates
can be bad for health because of a high content of Nickel.
The
carbohydrate which is used in silvering of mirrors is Fructose.
In
a nuclear reactor the material used for absorbing neutrons is cadmium.
Solder
metal is an alloy of lead and tin.
When
a child is born, its blood carries wastes for the 1st time.
Bone
is used as a fertilizer because it contains the plant nutrient Phosphorus.
The
energy of the Sun is mainly due to Nuclear Fusion.
Plants
release energy during Photosynthesis.
The
part of a plant from which turmeric obtained is Root.
Genes,
the hereditary units, are located in the Chromosomes.
The
oil which causes dropsy is Argemone oil.
Universal
donors are people with the bold group ‘O’.
Aquatic
animal with the most developed intelligence is Whale.
The
blood vessel which carries oxygenated blood to the liver is Hepatic Artery.
Beta
cells secrete Insulin.
In
the human body, fats are stored in the Adipose tissue.
Blood
does not clot in the blood vessels due to the presence of Fibrinogen.
The
DPT vaccine is given to young babies to protect them from Diphtheria, Whooping
Cough and Tetanus.
Haemophilia
is a genetic disorder.
The
blood vessel supplying blood to the kidney is the renal artery.
The
organ which stores carbohydrates as glycogen in the human body is Liver.
Optic
fibers are used in place of wire cables because they do not generate magnetic
fields.
A
device that converts images into Digital data that can be stored in a computer
is a scanner.
The
sparking of a diamond is due to total internal reflection of light.
In
a diesel engine, the high temperature needed to ignite the fuel is achieved by
compressing air in the cylinders.
Waves
that are required for long distance wireless communication are radio waves.
The
radiation initially produced in fluorescent tube is Ultraviolet.
Silver
nitrate solution is kept in brown bottles in laboratory because bottles stop
the passage of light through it.
Lead
pencil contains Graphite.
Mitochondria
contain enzymes for cellular respiration.
A
seed is a ripened Ovule.
In
the human body, Spleen secretes hormones as well as digestive enzymes.
Trypsin
is an enzyme.
Alum
is not present in cement.
Convex
lenses are used for the correction of long-sightedness.
A
transformer is used to increase or decrease AC voltage.
Food
is cooked in a pressure cooker quickly because Boiling point of water
increases.
The
chemical name for Baking Soda is Sodium Bicarbonate.
Mist
is caused by water vapors at low temperature.
The
1st computer language developed was FORTRAN.
The
total number of vertebrae in a human being is 26.
The
instrument that determines specific gravity of liquids is Gravimeter.
Joseph
Lister discovered antiseptic Surgery.
Carbon,
Hydrogen, Oxygen, Nitrogen are present in all proteins. Besides these four
elements, Sulphur is also present in some proteins. Some times, there may be
phosphorus and iron as well in a few proteins through they is never found
abundantly.
Normal
blood pressure of the human body is 80 mm Hg diastolic and 120 mm Hg Systolic.
In
hospitals, the oxygen tube for respiration contains oxygen and Helium.
Solder
is an alloy of copper.
Scientific
research studies have revealed that tobacco smoke contains “carcinogens”, which
are the main cause of cancer. These carcinogens include 7 types of polycyclic
hydrocarbons along with a radioactive element. This radio active element is
Zirconium.
The
major cause of ailments due to malnutrition among most Indian children from the
age group of 1-5 years is deficiency of protein.
Acid
rain is caused by pollution of environment by Nitrous Oxide and Sulphurdioxide.
A
biogas plant work to its maximum capacity when conditions are anaerobic and
temperature 400 C.
Chemical
composition of Pearl is Calcium Carbonate.
The
complete conversion of glucose in the presence of oxygen into carbondioxide and
water with release of energy is called Aerobic respiration.
The
most abundant elements in earth’s crust are Oxygen and Silicon.
One
well known example of parasitic protozoan is Plasmodium.
Atomic
mass unit is a unit of mass used to express atomic and molecular weights equal
to 1/12 of the mass of an atom of Carbon (c).
It
has been found that excessive use of cellular phone is likely to cause cerebral
malignancy.
Iron
does not for amalgams.
The
chemical used for removing air bubbles from the glass during its manufacture is
Potassium Carbonate.
Cast
Iron has got the highest carbon content.
The
gas that gives benzene on passing through a red hot tube is Acetylene.
The
information retrieval in a magnetic tape is always sequential.
A
green leaf placed in a dark room is illuminated by red light. The leaf will
appear Black.
Cholera
is mainly a water-borne disease.
Rows
of trees grown along the coastal areas to reduce the impact of cyclones are
known as Mangroves.
The
most effective pesticide for general use against most garden pests in
Malathion.
Dialysis
is the treatment given to a patient suffering from Kidney Problem.
The
drug which reduces Blood pressure is obtained from Rauwolfia Surpentina.
Modern
Forensic scientists are using a most recently developed tool, namely DNA Finger
Printing.
Water
from an artesian well flows up automatically due to Hydrostatic Pressure.
Mercury
is a metal.
TCP/IP
– Transfer control/ Internet Protocol.
Father
of e-mail is Tomlinson.
Smog
– Smoke + Fog.
The
colour of Ozone gas is Light Blue.
The
Ozone layer exists in Stratosphere.
SAN
(Sino atrial node) is also called Pace Maker.
Transformers
are of 2 types 1. Step up Transformer 2. Step down Transformer.
Electron
was invented by J.J.Thompson in 1897.
Neutron
was invented by Chadwick in 1932.
The
colour of I2 is purple Black.
Artificial
satellites are placed in Thermosphere.
Stainless
steel contains Iron, Nickel and Chromium.
Alternating
current is used in electroplating.
Periscope
is used in Sub marines.
The
smallest Enzyme is Peroxidase.
The
largest Enzyme is Catalase.
The
fastest enzyme is carbonic anhydride.
Methane
is released from Rice Fields in the most prominent quantities.
Potassium
is not a structural component of the Plant.
Misch
metal is widely used in the manufacture of cigarette lighters.
In
the human body, Cowper’s glands form a part of Reproductive system.
The
percentage of lead in lead pencil in 0%.
The
gas responsible for the swelling of bread in co2.
Helium
is preferred over hydrogen for use in airships because Helium is less reactive.
Vinegar
is a commercial name of Acetic Acid.
In
Vulcanization process Rubber is hardened by adding Sulphur.
Most
of the explosions in mines occur due to the mixing of Methane with air.
Blue
Green algae can serve as a bio fertilizer for Rice.
The
blood glucose level is commonly expressed as Milligram per deciliter.
Phytotron
is a facility to grow plants under controlled conditions.
Nichrome
is very hard and very ductile.
Insect
resistant cotton plants have been genetically engineered by inserting a gene
from a bacterium.
Soft
drinks such as colas contain significant quantities of Caffeine.
A
TV remote control unit use Microwaves to operate a T V set.
Hybridoma
technology is a new biotechnological approach for commercial production of
Monoclonal antibodies.
The
sensation of fatigue in the muscles after prolonged strenuous physical work is
caused by the accumulation of lactic acid.
Aluminum
surfaces are often anodized. This means the deposition of a layer of Aluminum
Oxide.
A
small pouch containing silica gel is often found in bottles of medicine tablet
or powder form because Silica Gel absorbs moisture.
The
universal Law of gravitation was propounded by Newton.
The
gravitational force with which the sun attracts the earth is the same with
which earth attracts the Sun.
If
the distance between the earth and the sun were twice, the gravitational force
exerted on the earth by the sun would be 1/4th of what it is now.
The
mass of a body is different from its weight because mass is a measure of the
quantity of matter whereas weight is a force.
A
body weighs maximum at poles.
A
person weighs more in lift, which is accelerating upward.
If
a body is taken from the earth to the moon its mass will remain the same but
weight will be different.
A
ball tied with a string to a rotating shaft revolves at uniform speed. As the
shaft is suddenly brought to rest the string starts getting round the shaft
with the angular velocity of the ball increasing.
One
finds it more difficult to walk on ice than on a concrete road because the
friction between the ice and the feet.
A
sheet of paper can be pulled out quickly from under a glass of water without
spilling the water. This phenomenon illustrates inertia.
A
horse pulling a Tonga moves forward due to the force exerted by the ground on
the horse’s feet.
When
the velocity of a body is doubled, its momentum is doubled.
The
work done in holding a weight of 20Kg at a height of 1 m above the ground is
Zero.
When
the speed of a body is doubled, its kinetic energy becomes quadruple.
Winding
a watch is actually the process of storing Potential energy.
A
long thread suspended from a fixed point, has a small mass swinging to and fro
at its lower end. The Kinetic energy is maximum in the middle of the swing.
Conservation
of energy means that energy can neither be created nor destroyed.
A
person climbing a hill bends forward in order to increase stability.
The
period of revolution of a geostationary satellite is 24 hours.
If
an apple is released from an orbiting space ship, it will move along with the
spaceship at the same speed.
The
density of sea water increases as depth and salinity increase.
When
as ship enters a sea from a river it rises a little.
A
steel ball floats on mercury because the density of mercury is higher than that
of steel.
Inside
an aeroplane, flying at a high altitude normal atmospheric pressure is
maintained by the use of air pumps.
Atmospheric
pressure is measured with a barometer.
The
atmosphere exerts enormous pressure on us. But we do not feel it because our
blood exerts a pressure slightly more than that of the atmosphere.
On
a barometer, mercury is preferred over water because mercury has high density
and low vapour pressure.
An
object weighs maximum in vacuum.
Four
solid cubes of different metals, each one having a mass of one kg, are weighed
in water Cube with minimum density weighs minimum.
A
stone is thrown into a deep lake. As it sinks deeper and deeper into the water,
the up thrust acting on it remains constant.
Raindrops
are spherical due to surface tension.
When
two mercury drops are brought into contact, they merge to form a bigger drop
because liquids have a tendency to possess minimum surface area.
On
a clean glass plate a drop of water spreads to form a thin layer whereas a drop
of mercury remains almost spherical because cohesion of mercury is grater than
its adhesion with glass.
The
swing of a spinning cricket ball in the air can be explained on the basis of
Bernoulli’s theorem.
A
train goes past a railway station at a high speed. A young boy standing on the
edge of the platform is likely to fall towards the train.
In
a sprayer the liquid rises in the tube due to lower pressure at the upper end.
A
football bounces when it falls on the ground because of its property of
elasticity.
In
cold countries alcohol is preferred to mercury as a thermometric liquid because
alcohol has very low freezing point.
The
science dealing with the study of phenomena at very low temperatures is known
as cryogenics.
On
heating a circular metallic disc with a circular hole at the centre, the
diameter of the hole will increase.
When
a certain mass of liquid is heated in a glass flask the liquid level falls first
and then starts rising.
When
a cube of ice floating on water in a beaker melts, the level of water in the
beaker remains the same.
If
water in a lake were to behave like other liquids, then in extremely cold
weather it would freeze from bottom to top.
The
temperature of the top of a frozen lake is 150 C. The temperature of
the water in the lake in contact with the ice layer is 00 C.
Fish
can survive inside a frozen lake because water near the bottom does not freeze.
When
water is cooled from 8o C to 00
C its volume decreases up to 4o C and then increases.
The
best conductor of heat among liquid is mercury.
An
iron hammer, lying in the Sun, appears much hotter than its wooden handle
because iron is good conductor of heat.
A
thermostat is a device for regulating temperature.
A
Pyrex number does not crack when hot water is poured into it because Pyrex does
not expand much on heating.
Woolens
keep us warm in winter because they do not allow our body heat to escape.
The
freezer in a refrigerator is fitted near the top so that it can cool the whole
interior by setting up convection currents.
By
the process of radiation, heat is transmitted from the filament of an evacuated
electric bulb to the glass.
Hot
coffee is poured simultaneously in four metallic tumblers painted outside with
different types of paints. After some time, the coffee will be found coldest in
the tumbler painted back.
Light
coloured clothes are preferred in summer because light colors are poor
absorbers of heat.
A
cup of hot coffee loses heat if placed on a metal table in a room by the
process of conduction, convection, radiation and evaporation.
In
a cup, tea cools from 90o c to 80o c in exactly one
minute. It will cool from 70o c to 60o c in more than one
minute.
Drinks
remain hot or cold for a long time in a thermo flask because of the presence of
air, which is a bad conductor of heat, in between the double walls and silver
coating on the inside of the double walls.
For
a given liquid, the rate of evaporation depends on the temperature of the
liquid, the temperature of air and the surface area of the liquid.
A
little ether on the palm gives a cooling sensation because ether evaporates.
Water
stored in earthenware cools because water oozing out of the pores evaporates.
During
summer, we feel comfortable under a fan because it sets the air in motion,
thereby increasing the evaporation of sweat.
Perspiration
is maximum, when temperature is high and air is humid.
Scalding
with steam is more severe than scalding by boiling water because steam contains
more energy than boiling water.
One
feels cold after a dip in sea water due to the evaporation of water on the
body.
The
surface of water in a pond remains cool even on a hot day because water
evaporates at the surface and evaporation causes cooling.
The
quantity of water vapour at atmosphere can hold increases with increase of
temperature.
The
hygrometer is an instrument to measure relative humidity.
The
boiling point of water depends on atmospheric pressure.
It
takes much longer to cook things in the hills than in the plains, because in
the hills the atmospheric pressure is lower than that in the plains and
therefore water boils at lower temperature.
Food
is cooked faster in a pressure cooker because due to high pressure the boiling
point of water is raised.
The
cover of a solar cooker is made of glass because glass allows sunlight into the
container but does not allow heat radiation out of it.
Light
waves are different from sound wave in that light waves are electromagnetic but
sound waves are not.
Infrared
waves have the longest wavelength.
The
layer of the atmosphere which reflects the radio waves back to the earth is
called ionosphere.
Radio
reception improves slightly during the night because sunlight affects radio
broadcasts to some extent during the day.
Television
signals cannot be received ordinarily beyond a particular distance due to
curvature of the earth.
Radar
is used for detecting and fixing the position of objects, e.g., aeroplane.
A
small hole in the window of a closed room forms an inverted image of outside
building on the opposite wall of the room. This happens because of the
rectilinear propagation of light.
A
lunar eclipse occurs when the earth comes between the sun and the moon.
A
solar eclipse occurs, when the moon comes between the Sun and the earth.
Corona
of the sun is visible during total solar eclipse.
The
image of an object formed in a plane mirror is virtual.
The
minimum length of plane mirror in which a person can see himself full length
should be nearly half his height.
If
you walk towards a plane mirror at a speed of 10cm/s then your image approach
you at a speed of 20 cm/s.
If
you stand in a room, where two adjacent walls are covered with plane mirrors,
the total number of your images formed will be 3.
Concave
mirror can be used to obtain the real image of an object.
Concave
mirror can be used as a burning glass.
A
dentist’s mirror is a concave mirror.
For
the rear view, motorists use convex mirror.
The
type of mirror used in the headlamps of cars is parabolic concave mirror.
When
a pencil is partly immersed in water in a slanting position, the immersed
portion appears bent towards the water surface.
The
sun remains visible for some time after it actually sets below the horizon.
This happens due to atmospheric refraction.
If
there were no atmosphere, the length of the day would decrease.
The
sun and moon appear elliptical near the horizon due to refraction.
The
twinkling of stars can be partly attributed to atmospheric refraction.
A
rainbow is formed by the dispersion and total interval reflection of light by
water droplets.
After
a shower of rain, a rainbow is seen opposite the sun.
When
white light passes through a glass prism, it gets dispersed into colours
because different colours have different speeds in glass.
Colours
which cannot be produced by mixing other colours are primary colours.
The
three primary colours are blue, green and red.
The
part of the camera which is analogous to the retina in the human eye is film.
The
accommodation of the eye is produced by the ciliary muscles.
In
old age, people have to wear spectacles for reading and writing because they
lose the power of accommodation.
The
sky appears blue because the atmosphere scatters blue colors more than the
others.
To
an astronaut, the outer space appears black.
In
upper space, astronauts can see stars during the day in all directions.
The
sun appears deep orange-red before it sets because its light has to traverse a
thicker atmosphere, therefore, other colours get scattered and do not reach us.
Soap
bubbles show multiple colours when viewed in white light because of the
interference of the reflected light.
The
technique of recording and reproducing three dimensional images of objects is
known as holography.
When
a wave goes from one place to another, it transports energy.
The
pitch (or shrillness) of a sound is determined by its frequency.
A
woman’s voice is shriller than a man’s due to higher frequency.
The
loudness of a sound wave is determined by its amplitude.
Sound
travels at maximum speed in steel.
Sounds
cannot travel through Vacuum.
Thunder
is heard much after a flash of lightning is seen because light travels much
faster than sound.
Mach number is used in connection with the speed of
aircraft.
Echoes
are produced due to reflection of sound.
A
clearly separate echo of a sound is heard when the minimum distance of the
reflecting surface from the source of sound is 17 mts.
The
walls and ceiling of an auditorium are covered with fibrous material, such as
glass fiber, to absorb sound and prevent echoes.
Bats
can fly in the dark because they are guided by ultrasonic waves produced by
them.
A
police van sounding its siren is moving away from an observer. The
pitch(shrillness) of the sound from the siren relative to its normal pitch is
lower.
A
device used for measuring the depth of the sea is called fathometer.
If
a bar magnet, tied in the idle with a thread were suspended at the north pole
of the earth, it would take a nearly vertical position with its north pole
pointing downward.
The
crackling sound, heard when dry hair is combed with a hard rubber comb, is due
to small electric sparks.
A
capacitor (condenser) is used in an electrical circuit to store
electric charge.
Soft iron would be most suitable for making an electromagnet.
Nichrome
wire is used as a heat element in many appliances because of its high
resistivity and its inability of oxidation in air when red hot.
Electric
motor converts electrical energy into mechanical energy.
The
starting current of an electric motor is much grater than the current flowing
after the motor reaches its normal running speed.
Energy
conversations in a loudspeaker are electrical to mechanical to sound.
The
device used for converting mechanical energy into electrical energy is called a
dynamo.
In
our houses we get 220 V ac. The value 220 represents effective voltage.
The
advantage of AC over DC is that it can be transmitted over long distances with
minimum power loss.
The
function of fuse in an electrical circuit is to break the circuit in case of
overloading or short-circuiting.
In
an electrical circuit, a fuse is connected in the live wire.
If
a fuse blows frequently, one should call an electrician.
The
material used for a fuse wire should have low melting point.
One
should not connect a number of electrical appliances to the same power socket
because this can damage the domestic wiring due to over heating.
An
electrical appliance is earthed to prevent shocks.
An
electric bulb has a filament made of tungsten.
The
filament of an electric lamp becomes white hot but the lead-in wires holding
the filament are only slightly heated because they have very low resistance.
Air
is completely removed from an electric bulb to prevent oxidation of tungsten
filament.
When
an electric bulb breaks, there is a mild bang due to the air rushing in to fill
the evacuated space.
A
common fluorescent tube contains mercury vapour at low pressure.
The
effective radius of atom is 10-10 mts.
X-rays
are produced when very high energy, electrons are stopped suddenly at a metal
target.
The
force between two protons (positively charged particles) is attractive or
repulsive depending on the distance between them.
In
the nucleus of Uranium-2354, there are a total of 235 protons and neutrons.
Phenomenon
of spontaneous disintegration of a heavy nucleus is termed as radioactivity.
Gamma
rays are produced during radioactive nuclear changes.
Gamma
radiations are used for sterilizing food stuffs, controlling pests and cancer
therapy.
Radio
isotopes are radioactive.
Fission
reaction takes place in a reactor as well as an atomic bomb.
Enriched
Uranium means uranium that has been enriched in isotope Uranium-235.
The
function of a moderator in a nuclear reactor is to slow down the secondary
neutrons.
A
breeder reactor is that which produces more fissionable material than it burns.
The
enormous energy released in an atomic explosion is due to the conversion of
mass into energy.
The
process by which energy is generated in the Sun is the fusion of Hydrogen.
The
astronomical unit (AU) is the mean distance from the centre of the Sun to the
center of the earth.
Constellations
appear to change their positions at different times of night because the earth
rotates about its axis.
The
star (other than the Sun) nearest to the earth is Proxima Centauri.
The
nearest star (other than the Sun), which is visible to the naked eye is Alpha
Centauri.
Light from the nearest star (other than the Sun)
reaches the earth in 4.2 years.
The
Pole star does not seem to move because it is in line with the earth’s axis of
rotation.
Saturn
has the prominent rings around it.
Mars
is known as the red Planet.
The
Planet closest to the Sun is Mercury.
The
heaviest among the inner planets is the Earth.
Mercury
and Venus do not have satellites revolving around them.
Jupiter
has the maximum number of satellites.
The
tail of a comet always points away from the sun due to solar radiation and
solar wind.
Halley’s
Comet was seen in 1910 and again in 1986.
We
see only one side of the moon all the time because the period of rotation of
the moon on its axis is equal to its period of evolution around the earth.
Solar
cells are the source of electric energy in an artificial satellite.
Treads
on the shoe soles are made to increase friction.
Broad
wooden sleepers are placed below the rails to reduce pressure exerted by the
train.
An
apparatus used for locating submerged objects is known as Sonar.
An
artificially satellite can be tracked very precisely from the earth by using
Doppler Effect.
A
GM counter is used for detecting radioactivity.
Stars
appear to move from east to west because the earth is rotating from West to
east.
On
a clear night we can see nearly 3000 stars with naked eyes.
The
Pole star is part of the Constellation Ursa Minor.
Planet
Neptune has 13 known moons.
Heavenly
matter landing on the earth’s surface is known as meteorite.
The
moon has equal periods of rotation and revolution.
Weight
of a person can be zero when he is falling freely or he is orbiting in a
satellite.
Mountain
roads wind up gradually and do not go straight up, because on winding roads
less force is needed to overcome gravity.
For
the same total weight and the same fuel supply, a multistage rocket is
preferred over a single-stage rocket, because the final velocity achieved by a
multistage rocket is higher.
The
earth and the moon are about the same distance from the sun, yet on the average
the earth is much warmer than the moon because the moon has almost no
atmosphere.
There
is no Doppler effect for sound when the source of sound moves at right angles
to the line joining the source and the observer.
Watt
is the unit of power.
Pascal
is the unit of pressure.
Joule
is the unit of energy.
Newton
is the unit of Force.
A
star with a mass of less than 1.4 solar masses will probably end its life as a
white dwarf.
Phobos
is the moon of the planet Mars.
Titan
is the moon of the planet Saturn.
Miranda
is the moon of the planet Uranus.
Ganymede
is the moon of the planet Jupiter.
Rocks
of Saturn are likely to float on water.
Ganymede
of Jupiter is the largest moon.
If
a proton and an electron are at equal distance from a positively charged plate,
then, electron will move towards the plate with acceleration nearly 2000 times
that of the proton.
Graphite
is used as a lubricant in heavy machines.
Hydraulic
brakes in automobiles work on Pascal’s principle.
A
hydrogen filled balloon rises only if its total weight is much less than the
weight of air it displaces.
A
barometer can also be used for determining altitudes and weather forecasting.
Dasymeter
is used to measure density of a gas.
Manometer
is used to measure the pressure of a gas.
Cryometer
is used to measure low temperatures.
X-rays
are electromagnetic waves.
The
light phenomenon taking place in a periscope is reflection and refraction.
Endoscope,
used by doctors for examining the inside of a patient’s stomach, works on the
principle of total internal reflection of light.
Ceramics
can be made to behave as a superconductor at a temperature of about 100 K.
Silicon
and Germanium are semi conductors.
In
an electric bulb, a little nitrogen or argon in introduced at low pressure to
prevent evaporation of the filament.
A
device used for converting A.C into D.C is called Rectifier.
The
faint illumination of dark side of the moon during a crescent phase is due to
sunlight reflected by the earth.
Venus
appears to be the brightest in the night.
The
only planet on which the sun rises in the west is Venus.
The
planet similar to our earth in mass, size, and density is Venus.
Ecliptic’
is the term used for the sun’s path in the sky during a year.
An
egg sinks in tap water but floats in a concentrated solution of salt because
the density of salt solution exceeds the density of egg.
In
cold regions, where temperature may fall below 0o C, farmers fill
their fields with water to protect their crops from damage because water has
high specific heat capacity.
The
part of the human eye which performs a function similar to that of aperture in
a photographic camera is pupil.
The
f-number in a photographic camera is equal to the focal length of the lens
divided by the diameter of the aperture.
The
inside of a photographic camera is coated black to avoid reflection of light.
A
photoelectric cell converts light energy to electric energy.
The
Hubble space telescope has fixed the age of the universe at 8-12 billion years.
In
Newton’s third law, the action and reaction forces act on different bodies and
are always equal.
As
a spaceship moves from a higher to a lower orbit, its speed increases.
An
astronaut on a space walk changes his direction by using a hand rocket.
The
self- maneuvering unit used by an astronaut works on Newton’s 3rd
law of motion.
Kepler proposed the laws of planetary motion.
Galileo discovered moons of Jupiter.
Copernicus proposed the Heliocentric theory.
Kepler
discovered that planets travel in orbits which are elliptical.
As
water freezes, its temperature does not change.
The
pupil of the eye adjusts automatically for amount of light.
A
fluorescent lamp and a television picture tube emit light by the phenomenon of
fluorescence, which is caused by beam of electrons in television tube and
ultraviolet rays in a fluorescent lamp.
The
velocity of light and radio waves are similar.
Colour is related to frequency.
Ultrasonics
is used for diagnosing abnormalities or diseases in human organs such as liver,
pancreas, kidneys, and heart.
Ultrasonics is used for mapping underground structures for
oil and mineral deposits.
A
diagnostic technique commonly known as “Ultrasound” is based on
recording echoes of extremely high frequency waves.
The
frequency of a sound wave is related to its pitch.
In
electric circuits, miniature circuit breakers (MCB) are preferred over fuses
because after removing the over load, the MCB can be reset very easily by
pressing a lever.
An
electron microscope can be used for viewing structure of bacteria and viruses.
In
Uranium-235, fission occurs when it captures a slow neutron.
Hydrogen bomb is based on the principle of uncontrolled
fusion reaction.
A
positron is an elementary particle.
A
positron is an elementary particle having mass equal to that of an
electron.
A
positron is an elementary particle with a charge equal and opposite
to that of an electron.
A
positron is an elementary particle with a charge equal to that of a
proton.
Radioactivity
is a property of atomic nuclei.
As
a metal brick. Thrown into a deep lake, sinks deeper and deeper, the buoyant
force acting on it remains constant.
Butter
floats in droplets on the surface of a hot soup. But when the soup cools, the
droplets spread out to form a thin layer on the surface. This happens because surface
tension of the soup increases on cooling.
On
the moon, an astronaut cannot drink lemonade with the help of a straw because
there is no atmosphere on the moon.
AM
(amplitude modulation) radio waves bounce off the ionic layers in the
atmosphere.
FM
(frequency modulation) radio waves penetrate the ionic layers.
FM
transmission is accomplished on a ‘line of sight’ basis.
A
remote control gadget (for TV etc.) has in it a small transmitter that emits
infrared signals.
A
body would weigh more at the poles than at the equator because equatorial
radius is greater than polar radius and also due to the rotation of the earth
about its axis.
A
stone tied at the end of a string is whirled in a circular orbit. If the length
of the string and the velocity of the stone are doubled, the tension in the
string is also doubled.
Cooling
inside a refrigerator in not proper when a thick layer of ice deposits on the
freezer because Ice is a bad conductor of heat.
Water
is a highly effective coolant for a car engine because water has very high
specific heat capacity.
All
the colours on a TV screen are produced from red, green and blue.
A
dynamo, which is said to generate electricity, actually acts as a converter of
energy.
A
neon sign emits red light which comes from a luminous gas at low pressure.
Electron
and positron is the particle and anti particle pair.
In
a stable nucleus the electrostatic force between protons is weaker than the
nuclear force.
The
critical velocity of an object falling in a viscous medium depends on the
coefficient of viscosity of the medium, the weight of the object and the size
of the object.
The
failure of light to travel strictly in a straight line is known as diffraction.
Doppler
Effect is applied to find out whether a star is approaching earth or receding
away from it.
Doppler
Effect is applied to find out the speed of rotation of the sun.
1
KB is equal to 1024 bytes and 1 MB is equal to 1000 KB.
A
computer’s ‘clock-speed’ is measured in megahertz and gigahertz.
The
working principle of a washing machine is centrifugation.
Endoscope
and periscope devices are based on the phenomenon of total internal reflection.
If
a person looks at a coin which is in a bucket of water, the coin will appear to
be closer than it really is.
If
a person under water looks at a coin above the water surface, the coin will
appear to be at a higher level than it really is.
Barium
in a suitable form is administered to patients before an X-ray examination of
the stomach, because barium is a good absorber of X-rays and this helps the
stomach to appear clearly in contract with the other regions in the picture.
Cobalt
-60 is commonly used in radiation therapy because it emits gamma rays.
Low
temperatures (Cryogenics) find application in space travel, surgery and
magnetic levitation.
An
ordinary light bulb has a rather short life because the filament wire is not
uniform or bulb cannot be evacuated completely.
The
mid-air swing of a spinning football can be explained on the basis of Bernoulli’s
principle.
If
the current flowing through a heater coil is doubled, the heat produced will
become four times.
The
working of Hovercraft, Helicopter, Rocket & Lawn Sprinkler are wholly or
partially explained by using Newton’s third law of motion.
Water
is a bad conductor of heat but a good conductor of electricity.
Light
travels faster in air than in water.
The
oxygen that keeps us alive is a product of photosynthesis that comes from
water.
awesome stuff but pls provide pdf files
ReplyDeletethanks for educate me about general-science GIS jobs in hyderabad
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