Sunday, December 30, 2007

Working of a Photocopier

  • The drum is shown, it comprises of a coating of selenium. Selenium is a photo conductive material; the property of a photo conductive material is that when light falls upon it, it gets charged. The drum gets charged by high voltage wire. The document to be photocopied is illuminated by light, the white part of the document reflects maximum amount of light, when this light falls on the drum, the negative charged gets diminished by earthing; the written material on the document reflects least amount of light, and corresponding areas of the drum have negative charge. Thus a virtual electrical image is formed on the drum.
  • The toner are small particles of ink which are positively charged, they get attached to the negatively charged particles on the selenium.
  • The paper which is inserted is attributed a negative charge, which is higher in magnitude as compared to the negative charge on the drum. The toner particles get attached to the paper. The toner is melted and fused in the paper, by a combine action of heat and rolling effect.
  • The drum continuously roates during the process of photocopy. Before the next cycle of photocopying begins, the drum is discharged.

Tuesday, December 25, 2007

The Big Toe- world's largest bike

The Big Toe is the world's largest bike. This monster is 2.3m(7.5 feet) high and 5m wide, weighing an astonishing 1645kg.

t has custom designed hydraulic suspension and small supporting wheels to keep it upright. The control panel has the start button and a 5000W speaker with CD player is built within the bike.

It has a top speed of 100km/hr(62mph). It is more of a show bike rather than a street bike. It is not designed to travel at high speeds. It is powered by
1975 Vintage Type E Jaguar SOHC 2 valve 60 degree 300HP 5.3L 12cylinder engine. Intake comes from 45mm twin choke Weber carburetors and a custom stainless muffler system handles the exhaust.

The man responsible for this bike is Tom Wiberg of Sweden. This bike is listed in the
Guinness Book of World records as the tallest driveable motorcycle in the world.

Sunday, December 16, 2007

did you know?

In this thread I will post some interesting science facts :-

  • did you know, a fly when alighted on top of a steel bar causes the bar to bend under its weight. the magnitude of bend is extremely small(1/1000 of a centimeter).
  • did you know, if a set of fine scales is arranged, so that one scale is kept dark and light is allowed to fall on another scale, the lighted scale will sink slowly. Light has "weight"; the pressure of light on earth's surface is calculated as 2 pounds per square mile.
  • did you know, there are very few animals on this planet which are not eaten by something else. One of them is the firefly. The adult firefly with its glowing body has no know predator.
  • did you know, every word we speak requires the use of 72 muscles in our body.
  • did you know, that a flea accelerates from a standstill to 3 feet per second in less than two thousand of a second subjecting it to a force of 150G. This is roughly equivalent to the force that a driver will experience driving a truck in a brick wall at the speed of 200 miles/hour.