Everyday Science Exercise 1 (Physical Properties)

Everyday Science Exercise 1 (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 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