Title: Summative Assessment
Course: MNPCC Physics > Section: Electromagnetic Waves

This quiz will show you if you learned everything you were supposed to during this unit.

Q: How does wavelength, frequency and energy change as you go from radio waves to gamma rays in the electromagnetic spectrum?
- Wavelength decreases, frequency increases and energy increases. (Correct.)
- Wavelength increases, frequency decreases and energy decreases. (That is exactly opposite.)
- Wavelength increases, frequency increases and energy increases. (Wavelength and frequency must always do the opposite.)
- Wavelength decreases, frequency decreases and energy decreases. (Only wavelength is correct.)
A: Wavelength decreases, frequency increases and energy increases.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: What are em waves?
- Perpendicular oscillating electric and magnetic fields. (Correct)
- Parallel oscillating electric and magnetic fields. (Perpendicular.)
- Perpendicular oscillating electric charges and magnets. (fields!)
- Parallel oscillating electric charges and magnets. (perpendicular fields.)
A: Perpendicular oscillating electric and magnetic fields.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: A green photon has just enough energy to knock and electron loose from a metal sample.  Which other type of photon would also be able to knock an electron loose?
- Violet (Correct.)
- Infrared (The energy would be too low.)
- Yellow (Yellow is lower in energy than green.)
A: Violet
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: When light passes through a diffraction grating and makes the characteristic diffraction pattern, is light behaving more like a particle (really small marble), a wave or both?
- Wave (Correct.)
- Particle (marbles can't interfere with each other.)
- Both (marbles can't interfere with each other.)
A: Wave
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: In what situation will a curved mirror be able to make a real image?
- Concave and outside of the focus. (Correct)
- Concave inside the focus. (That will be a magnified virtual image.)
- Convex outside the focus. (Convex can only make virtual images as the focus is in back.)
- Convex inside the focus. (Convex can only make virtual images as the focus is in back.)
A: Concave and outside of the focus.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Under which condition will a lens form a real image?
- A convex lens with the object outside of the focus. (Correct.)
- A convex lens with the object inside of the focus. (It must be outside the focus.)
- A concave lens inside of the focus. (Concave lenses can only make virtual images.)
- A concave lens outside of the focus. (Concave lenses can only make virtual images.)
A: A convex lens with the object outside of the focus.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: The refractive index of air is often given as 1.  Given that light travels slightly slower in air than in a vacuum, the refractive index of air should actually be...
- Greater than one. (Correct.)
- Less than one. (Nothing can have a smaller refractive index than one.)
- Equal to one. (That would require air having the same speed of light as a vacuum.)
A: Greater than one.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Which of the following are divergent optical devices?
- Convex mirrors and concave lenses. (Correct.)
- Concave mirrors and convex lenses. (Opposite.)
- Concave mirrors and lenses. (Only the concave lens.)
- Convex mirror and lenses. (Only convex mirrors.)
A: Convex mirrors and concave lenses.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: A yellow light is illuminating a shirt with a cyan pigment.  What color will the shirt appear?
- Green (Correct.)
- Yellow (The cyan pigment subtracts out the red.)
- Red (The cyan pigment subtracts out the red.)
- Blue (There is not blue component to yellow light.)
A: Green
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Three students are attempting to measure the size of the gap in the grooves of a cd with lasers.  One student is using a red laser, on e a green and one a blue.  Which laser will experience the most diffraction?
- Red (Correct)
- Green (Having the middle wavelength it will experience a middle level of diffraction.)
- Blue (Having the shortest wavelength it will diffract the least.)
A: Red
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: A physicist is pulled over for speeding.  The officer states they had run a red light.  The physicist responds that to them it appeared green because of the Doppler Shift.  The police officers agrees and writes them a speeding ticket instead.  For a red light to appear green was the physicist seeing it as they approached or in the rear view mirror as they moved away?  And why?
- Approached - causes a shift to a higher frequency. (Of course no car can go that fast!)
- Approached - caused the light to appear a lesser frequency. (Approaching shifts the frequency higher.)
- Receded - causes a shift to a higher frequency. (Moving away causes a shift to lower frequency.)
- Receded - caused the light to appear a lesser frequency. (Going to a lesser frequency would mean appearing in the infrared, not green.)
A: Approached - causes a shift to a higher frequency.
If right: Your answer is correct.
If wrong: Your answer is incorrect.