Physics

[abhishek_isverma]

I am having some confusion about electric current and voltage. What is the difference between these two.
One more question that why rainbow is formed in 'Arc' shape only?

[vinod]

When we see rainbows it usually appears as an arcs shape. However, rainbows are formed as a circle. The light from the sun is being refracted (bent) by the droplets over a certain angle (about 42 degrees) .This angle is so big that the rainbow appears centered on the point opposite the sun. This point is called the antsolar point that the rainbow seems to form around . The bow shape is actually part of a circle of light that is cut off by the horizon that obstruct it. Thus, the lower the sun is in the sky the more one will be able to see more of the rainbow (a larger bow). It is however possible to see the full circle of a rainbow at a high altitude such as in an aero plane. This is due to the fact that the horizon do not block the observer point of view.

more info:
http://universalfacts.blogspot.com/2006 ... auses.html (http://universalfacts.blogspot.com/2006/04/how-rainbows-are-formed-what-causes.html)