A monochromatic red laser beam emitting 1 mW at a wavelength of 638 nm is incident on a silicon solar cell. Find the following: a. The number of photons per second incident on the cell b. The maximum possible efficiency of conversion of this laser c. beam to electricity

Explanation:

First we calculate the energy of the photon

E=(Planck constant × speed of light in vacuum)÷ wave length

E=

Next we find the total energy per second

total energy=

Next we calculate the number the photon per second

= total energy ÷ energy of 1 photon

=

which statement about this sum is true? −245+2.7

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.