One of the most surprising things about a superconductor is that
it has NO electrical resistance. The resistance doesn't just become
very very very small. It becomes literally completely zero. (This is
a big part of the reason why it's called a "super-conductor".)
If you start an electric current flowing in a superconductor, you can
connect the ends of it together, and the current keeps going around
and around the loop and never dies out !
Answer:
The index of refraction of the first medium must be higher than the index of refraction of the second medium
Explanation:
Snell's law describes the behaviour of light at the boundary between two mediums:
where
n1 and n2 are the index of refraction of the two mediums
are the angle between the direction of the light ray and the normal to the interface
We can rewrite the condition as:
Let's assume now that the light is travelling in the first medium with a very large angle with respect to the normal to the surface, i.e. , so that . In this case, we have
We notice that if , the ratio on the right is larger than 1, and so the term should be also larger than 1: but this is not possible of course, since the sine function is always less than 1. Therefore, in this case total internal reflection occurs, because no refracted ray is produced.
Answer
A molecule with seesaw molecular geometry has a bond angle of 90° and 120°.
Seesaw is a type of molecular geometry where there are four bonds attached to a central atom.
Bond is observed in the shape of playground seesaw that is why it is known as a seesaw bond.
Four bonds attached to the central bond formed results as tetrahedral or square planar geometry.
In see-saw, shape maximizes the bond angle of the lone pair and the other atoms in the molecule.
lone pair in the equatorial position offer 120 and 90-degree bond angles whereas bond angle will be 90-degree bond angles if placed at axial position.