PHYSICAL PROPERTIES

 

·   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 1/10^th of a second

·   Image persists for about 1/10^th 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 motorcycles.

·   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.

·   Liver to make bile, which is stored in gall bladder, uses some of the chemicals from the recycle of old cells.

·   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