Answer:
DONORS: If the material for which it substitutes has more electrons than the original
ACCEPTORS: If the replacement material has fewer electrons than the original material
Fermi level: the point where the probability of finding the last electron is ½
Explanation:
When in a semiconductor material a small fraction of an element is replaced by another with different valences, an excess charge is created.
If the material for which it substitutes has more electrons than the original, there is an excess of electrons, these excess electrons are weakly bound in the material and their orbits are large, in an energy versus moment diagram their energy places them a little more below the conduction band, these materials are called DONORS.
If the replacement material has fewer electrons than the original material, one electron is missing to complete the bonds, so there is a movement of the other electrons, an easier way to analyze this movement of the (n-1) electrons is to suppose that The missing charge has a positive charge and to study its movement, this positive charge is called a hole, its binding energy is small so the orbit of the hole is large, in an energy diagram it is located a little above the band of valence, these are called ACCEPTORS
The Fermi level is defined as the point where the probability of finding the last electron is ½, when the temperature is changed the density of states of the bands changes, therefore the location point moves, but its [probability remains ½
I believe this battery is called Sheet battery.
Sheet battery is a flexible, ultra thin energy storage and production device formed by combining nano tubes with a conventional sheet of cellulose based paper. It acts as both a high-energy battery and super-capacitor, combining two components that are separate in traditional electronics.
Answer:
4.2 m
Explanation:
Note: If energy is conserved, i.e no work is done against friction
Work input = work output.
Work output = Force output × distance,
Work input = force input × distance moved moved.
Therefore,
input force×distance moved = output force × distance moved........................Equation 1
Given: input force = 80 N, output force = 240 N, output distance = 1.4 m
Let input distance = d
Substitute into equation 1
80×d = 240×1.4
80d = 336
d = 336/80
d = 4.2 m.
Thus the rope around the pulley must be pulled 4.2 m
