Light, Mirrors and Lenses Flashcards
What is the speed of light?
c = 3*10^8
What is the wavelength of visible light?
700 nm - 400 nm
Red - violet
What is the angle of incidence equal to?
The angle of reflection
What is the equation of the index of refraction?
n = c / speed of medium
The more the refraction, the bigger “n” is
What is the index of refraction of light in a vacuum / air?
n = 1
What is snells law?
n1sin(theta)1 = n2sin(theta)2
When is index of refraction “n” gets bigger what happens to sin theta in snells law?
It gets smaller because the larger the “n”, the more refraction occurs
If we look at a fish in water with n = 1.33, is the fish father away than it seems or closer than it seems?
It is closer than it seems?
What is the equation for critical angle?
sin theta of critical = n2 / n1
What is the critical angle?
It is when the refractory angle is 90 degrees to the normal
What happens to light being transmitted above the critical angle?
It is reflected
Does sound speed up when going from air to liquid?
Yes
Diffraction vs dispersion?
Diffraction is the spreading out waves as if emerging from a new point after coming across an obstacle
Dispersion is the splitting up of white light in a prism
What do higher frequency of light express in terms of indexes of refraction?
They experience higher indexes of refraction
What is polarization in light?
When one direction of oscillation if privileged over another
What is plane polarized light?
Light goes up and down when seen from the front.
Remember biophysical chemistry
What is circular polarized light?
Two perpendicular electric field components oscillate 90 degrees out of phase with each other
What is the focal length equation?
(1 / focal length) = (1 / object distance) + (1 / distance of image formed)
What is the magnification equation of lens?
magnification = ( - distance of image formed) / (distance of object)
What is the focal length of a converging optics (concave mirror and convex lens)?
Focal length is always positive
What is the focal length of a diverging optics (convex mirror and concave lens)?
Focal length is always negative
Is the image distance where light actually goes positive or negative?
It is positive
For lens it’s past them while for mirrors it’s before them since they reflect light
What is a real image?
Image shown where light converges (they are flipped)
Real images have “i” that is positive
What is a virtual image?
Image shown where light does not converge (not flipped)
Virtual images have “i” that is negative
What is the equation of lens power (units in diopters)?
P = 1 / f
What is the unit diopter?
It is equal to meters
so 7 diopter is equal to 7 m which is equal to 700 cm
What are the types of lens of near nearsightedness and far farsightedness?
Converging for far and diverging for near
What is myopia?
Eye focuses light too much and can’t reach retina (near sight)
What is hyperopia?
Eye does not bring light into focus at the retina (far sight)
