• 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 center 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.
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