•
Theory of mutation was propounded by Hygo de Vries.
•
A theory of acquired character was given by Lamark.
•
Charles Darwin is famous for his theory of struggle for
existence and survival of the fittest.
•
Sigmund Freud is called as the father of modern
psychiatry and psychology.
•
Energy stored in stretched spring is Elastic Potential energy
•
Energy stored in fossil fuels is chemical energy
•
Radio waves are Electromagnetic waves
•
A.C voltage is analogue quantity
•
Optical fibers work on polarization of electromagnetic waves
•
Condenser is used to collect the charge
•
In diesel engine ignition takes place by compression
•
A radar uses radio waves to detect enemy aircraft
•
Law of floating bodies was given by Archimedes
•
Particle with +ve charge but mass equal to electron is positron
•
Nucleus of an atom has +ve charge.
•
Bosons are Photons and
Mesons
•
There is no neutron in the atom of hydrogen
•
Quark is an atomic particle. Scientists think that
proton and neutrons are themselves made of
still smaller particles called quarks
•
Muttons are particles of atom
•
John Dalton, an English scientist, gave Atomic Theory
in 1803 describing atom as the smallest unit
of an element
•
Gas in children’ s balloon is Helium
•
Weight of electron = 9.1 x 10 power -31 kg
•
Charge on electron = 1.6 x 10 power -19 coulomb
•
Weight of proton = 1.66 x 10 power -27 kg
•
Charge on proton = 1.6 x 10 power -19 coulomb
•
A proton is 1836 times heavier than an electron
•
Ordinarily and atom is a neutral particle
•
Ernest Rutherford, a New Zealander, in 1908 discovered
Atomic Nucleus
•
Speed of sound is faster in hot air than in cold air
•
Ultrasonic are sound waves of high frequency = 12000
cycles/sec and higher
•
Sound travels faster in moist air than in dry air
•
Sound travels more rapidly in solids
•
Maximum limit of sound beyond which a man can become
deaf is 129 decibel
•
Audible sound is 20-20,000 cycles/second
•
Inaudible sound >20,000 cycles/second
•
Velocity of sound at 0 deg: C is 331.7 m/s
•
Echo can only be produces when the distance of the
obstacle is at least 17 meters
•
When we hear a sound, its impressions remain in our ear
for 1/10th of a second
•
Image persists for about 1/10th of second in our eye
•
For creating a persistence of vision, pictures are
projected at the rate of 10 or more/sec
•
Nuclear Energy is not a source of alternative energy.
•
Videotape used in camcorders to record audio and video
signal employee fine grains of iron oxide.
•
Temperature inside a refrigerator is 40 deg: F
•
The laws of reflection were first discovered by a al- Hazen
•
0.200 grams are equal to one carat.
•
One million cycles per second is called Megahertz.
•
Carbon fiber is made by heating textile fibers. These
are used in tennis rackets and racing yacht
•
Catalytic converter reduce the harmful fumes the engine emits
•
If you double the voltage you double the current (Ohm’s law)
•
What product uses the most silver-Camera Film
•
The speed of sound depends on the medium through which
the waves are passing. The speed of sound in gases depends on what? Density
•
Two or more molecules of carbohydrates are linked
together through glycosidic bond
•
peptide bond b\w amino acids, joined to form proteins,
is the linkage b/w N and C
•
An android is any robot that: has the ability to make
decisions and formulate plans
•
Semaphores were used between sailors for many years to
communicate between ships
•
One of the first long distance communication system
invented in 1790 was the semaphores towers
•
Telegraph was invented in 1821
•
Telephone was invented
in1876
•
Us inventor Samuel More developed the system of dots
and dashes of telegraph that was known as
Morse Code
•
Scientist now think that protons and Neutrons are
themselves made of still smaller particles called quarks.
•
Portable gadgets = Mobile phones and portable TVs.
•
Derailleur gears are used in Bicycles.
•
Motor – cross race is for motor cycles.
•
Cantilever brake used in Bicycle.
•
Speed of light 300,000 kilometers per second.
•
Engineers use electronic theodolite and range-finder to
measure the distance and angle to calibrated staff.
•
Centigrade and Celsius temperatures are same below
freezing point.
•
which instrument is used to measure pressure? Manometer
•
the velocity of light was first measured by Olaf Roemer
•
centigrade and fahrenheit scales gives same readings at
32 degrees
•
The first European scientist who refuted the belief
that the earth was the centre of the universe was Copernicus.
•
Mobile phones transmit message using radio-type waves
called microwaves
•
Super conductors are also strong diamagnetic this means
they strongly repel magnets.
•
Super conductors are used in very fast computers and
also in trains like Maglevs.
•
Electronic theodolite and range finder measures and
distance and angle.
•
A fluorescent light is a glass tube containing gas
which produces UV light when current passed
trough it. Tube is coated with phosphor which glows when UV hits it.
•
Some of the chemicals from the recycle of old cells are
used by liver to make bile which is stored in
gall bladder.
•
Which is lighter, gold or plastic? Plastic
•
Lasers are a special source of light called coherent
light this means all the light waves are in step with each other and travel in
same direction
•
Laser produce light of one particular wavelength and it
is s single, pure color.
•
The first hologram was make in 1962
•
Laser = Light Amplification by Stimulated Emission of Radiation
•
Quartz-halogen bulbs are used in overhead projectors
and spotlights
•
Helium is uses to fill airships and balloons
•
Helium is used to pressurize hydrogen fuel in rockets
and the air in diver’s air tanks
•
Apart from radon, which is radioactive, the noble gases
are used in lighting.
•
The noble gases have very low boiling points.
•
Liquid helium is the coldest substance.
•
A gas only becomes liquid at -268.9 deg: C
•
Combustion is a kind of oxidation reaction.
•
At room temperature the particles in air travel at
around 1800 km/h the same speed as a bullet fires from a rifle.
•
Generators convert mechanical energy into electrical energy.
•
The principle behind the generator is electromagnetic
induction. It was discovered by Michael Faraday.
•
Lovell telescope is at Jodrell Bank the site for space observatory
•
Nicolous Copernicus (1473-1543) was born in Poland and
was the first to explain the solar system.
•
Derailleur gear are used in bicycles
•
Cantilever brake is also used in bicycles
•
Static electricity makes a balloon stick to the wall
after you have rubbed it on your hair.
•
John Bardeen, Walter Brattain and William Shockley in
1947 used a semiconductor called germanium to make the world’s first transistor.
•
A diode conducts electricity easily in one direction
but resists the flow of electricity in the other.
•
A capacitor stores electric charge. Capacitors are
important components for making timers.
•
Capacitors are used in filtering circuits like treble
and bass in hi-fi
•
Transistors can be used as logic gates
•
Energy value of food items is expressed in kilojoules
(kj) or thousands of joules.
•
British scientist James Prescott Joule discovered the
principle of conservation of energy.
•
Which one of the following statements regarding sound
is true? Its source is always a vibrating material.
•
Weight of an object put in a satellite orbiting in
space around the earth is reduced to zero
•
Movie camera take pictures at rate of 24 pictures per second
•
Density of water is 1
•
Water expands as it freezes to ice. This makes ice less
dense than water which causes ice to float.
•
Heat flows in three ways conduction, convection and radiation
•
A concave lens is used for the correction of the Hyperphobia
•
Silver metal has the highest electrical conductivity.
•
Mohr’s scale hardest substance is diamond - what's the
softest: Talc
•
RAYS AND WAVES
•
Gamma rays are considered the death rays.
•
Gamma rays travel with the velocity of light
•
Gamma rays have maximum penetrating power
•
Shortest wavelength among alpha, beta and gamma is of
gamma rays
•
Laser rays are used in micro surgery
•
Alpha radiations produce burns on human body
•
Newton proved that sunlight consists of different colors
•
Beta rays are fast moving electrons.
•
Color with shortest wavelength is Blue
•
Violet have shortest wave length and Red has longest
wavelength (vibgyor)
•
Red light’s wave length is 11800 waves/cm (< infra red)
•
Least deviated color in prism is red
•
Greatest deviated color in prism is indigo (chk violet)
•
Violet light’s wave length is 23600 waves/cm (>
ultra violet)
•
Ultraviolet rays are less than 3000 deg: A
•
Greatest value of wavelength is of infra red
•
Visible waves are between 400-700 nanometers.
•
MOTE = Million Tons of oil equivalent
•
REM = Roentgen equivalent in man
•
Transverse waves can only be produced in solids
•
Longitudinal waves can be produced in solids, liquids
and gases
•
On passing thought food stuff, x-ray can kill bacteria
•
Violet color of light t ravel thought glass with
minimum speed
•
There is no wavelength of light for color brown.
•
White light is a mixture of all the colors in the rainbow.
•
Blue has the shortest wavelength and red the longest.
•
Radio waves also come from sun and outer space.
Astronomers use radio telescope to hear them.
•
Radar uses microwaves.
•
Anything that is warm produces infrared waves including
us. The hotter the thing the more IR.
•
Infrared waves are used in TV remote control.
•
X-rays have shorter wavelength and more energy than
ultraviolet rays.
•
Gamma rays come from radioactive materials. They are
used to kill cancers.
•
Without exposure to ultraviolet light our bodies would
not be able to make vitamin D.
•
UHF, ultra high frequency are radio waves used for TV broadcast
•
Microwaves are used in radar, mobile phones, microwave
oven, communication network
•
Each light color is of different wavelength.
•
Red light has the longest wavelength while violet light
has the shortest.
•
Waves with a longer wavelength than red light are
invisible they are called infrared waves.
•
Invisible Ultraviolet wave have wavelength shorter than
violet light.
•
Red, Blue, Green are prime colors.
•
Red + Blue + Green =
white
•
The wavelength of visible light is between 1350-2500
•
An object that reflects all the light looks white.
•
Loud speaker converts electrical energy into sound energy.
•
Light coloured clothes are generally worn in summer
•
The electrical device which transform voltage : transformer
•
A nuclear reaction in which two or more than two
lighter nuclear are fused together to form a
relatively heavier one : nuclear fusion
•
The three colours combination which produces the
sensation of white light : Red green and blue
•
The clear sky looks blue because of dispersion of light
•
When light waves travel from air to glass the
wavelength and velocity variables are affected.
•
Electrical lines of forces are imaginary.