Tuesday, July 20, 2010

1) persistence of vision --cinema

2)television--J.L Baird.

3)asia biggest astronnomical telescope-kavanur.

4)sound travel maximum speed in steel.

5)atomb bomb -nuclear fission


6)hydrogen bomb-nuclear fusion.

7)sudden fall of atmospheric pressure indicates--storm.

8)sudden decrease in barometric pressure indicates a stormy weather.

9)Matter is commonly said to exist in four states : solid, liquid, gas and plasma.

10)sky is blue--due to scattering of light.

10A)rain bearing clouds look black--large no. of water droplets absorb all the sunlight.
11)primary colours --red, green ,blue.

12)x-ray-roentgen.

13)radioactivity--henry becqurel.

14)temperature at which farenhiet and centigrade have same reading--40 c


15)exclusive principle--pauli

16)rainbow-total internal reflection.

17)wave theory--huygen.


18)water drops are spherical --surface tension.


19)colour of light is determined by its wavelength.


20)least distantance of distinct vision is equal to

21)raman effect is due to scattering of light.

22)weak acid:

A weak acid is an acid that dissociates incompletely. It does not release all of its hydrogens in a solution, donating only a partial amount of its protons to the solution. These acids have higher pKa than strong acids, which release all of their hydrogen atoms when dissolved in water.

Examples of weak acids include acetic acid (CH3COOH) and oxalic acid (H2C2O4)

23) liquid metal-mercury.

24)at sunrise and sunset sky appears red- red light intensity is more.

25)power of lens is measured in - dioptre.

26)bowmans capsule functions as a filter.

27)Laser-coherent waves.

28)pyrometer--measure high temperature.

29)fuse wire made of -lead tin alloy.

30)most basic of all test instrument--galvanometer.

31)sound waves are -longitudinal waves.

32)Refractive index is highest for diamond.

33)unit of refractive index--no unit.

34)

  • Conductors:
  • silver
  • copper
  • gold
  • aluminum
  • iron
  • steel
  • brass
  • bronze
  • mercury
  • graphite
  • dirty water
  • concrete.

  • Insulators:
  • glass
  • rubber
  • oil
  • asphalt
  • fiberglass
  • porcelain
  • ceramic
  • quartz
  • (dry) cotton
  • (dry) paper
  • (dry) wood
  • plastic
  • air
  • diamond
  • pure water
35)growth of baby in uterus is found using ultra sound.

36)when a wave goes from one place to another it transmits energy.


37)Artifical satellite can be tracked very precisely from the earth using doppler effect.


The Doppler effect (or Doppler shift), named after Austrian physicist Christian Doppler who proposed it in 1842, is the change in frequency of a wave for an observer moving relative to the source of the wave. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from an observer. The received frequency is higher (compared to the emitted frequency) during the approach, it is identical at the instant of passing by, and it is lower during the recession.

38)when a vehicle passes,tv reception gets distorted due to --spark plug creating electromagnetic disturbances.

39)waves received by our television--microwaves.

40)

The Chandra X-ray Observatory is a satellite launched on STS-93 by NASA on July 23, 1999. It was named in honor of Indian-American physicist Subrahmanyan Chandrasekhar who is known for determining the maximum mass for white dwarfs. "Chandra" also means "moon" or "luminous" in Sanskrit.

Chandra Observatory is the third of NASA's four Great Observatories. The first was Hubble Space Telescope; second the Compton Gamma Ray Observatory, launched in 1991; and last is the Spitzer Space Telescope. Prior to successful launch, the Chandra Observatory was known as AXAF, the Advanced X-ray Astrophysics Facility. AXAF was assembled and tested by TRW (now Northrop Grumman Space Technology) in Redondo Beach, California. Chandra is sensitive to X-ray sources 100 times fainter than any previous X-ray telescope, due primarily to the high angular resolution of the Chandra mirrors.

41)


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