Answer:
Population inversion, in physics, the redistribution of atomic energy levels that takes place in a system so that laser action can occur. Although absorption and emission of energy is a continuous process, the statistical distribution (population) of atoms in the various energy states is constant. ...
laser inversion is photon that can stimulate the production of other photons of exactly the same wavelength because of stimulated emission of radiation.
Explanation:
Ionic bond.
In the ionic bond one atom loses one or more electrons, leaving the atom with positive charge, and the other atom accepts those electrons standing with negative charge.
If the angle is either 0 or 180, that means that there is either negative or positive work, so A and D are not correct.
If the angle is 45, then there is still some work involved.
The only option where there is no work done by a force is B. when the angle is between the force and displacement is 90.
Answer:
The magnitude and direction of the acceleration of the particle is 
Explanation:
Given that,
Mass 
Velocity 
Charge 
Magnetic field 
We need to calculate the acceleration of the particle
Formula of the acceleration is defined as


We need to calculate the value of 


Now, put the all values into the acceleration 's formula


Negative sign shows the opposite direction.
Hence, The magnitude and direction of the acceleration of the particle is 
Answer:
The minimum thickness = 83.92 nm
Explanation:
The relation between the wavelength in a particular medium and refractive index 
where ;
= wavelength of the light in vacuum
n = refractive index of medium with respect to vacuum
For one phase change :

Replacing 1.43 for n and 480 nm for λ; we have:

t = 83.92 nm
Thus; the minimum thickness = 83.92 nm