Title: Mid-Unit Assessment
Course: MNPCC Physics > Section: Electromagnetic Waves

Use this quiz to check on how you are progressing with the concepts covered in this unit.

Q: A blue light is illuminating an apple that contains a red pigment.  What color will the apple appear?
- Black (Correct.)
- Blue (Red pigments absorb blue.)
- Red (There is no red light to be reflected.)
- Magenta (Red and blue light do mix to make magenta, but the apple is not a source of light.)
A: Black
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Which term means a device that would bring light rays that are incident parallel to each other together?
- Convergent (Correct.)
- Divergen (Diverge means go apart.)
- Transvergent (Not even a word.)
A: Convergent
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: How does the frequency of microwaves compare to the frequency of ultraviolet waves?
- Ultraviolet waves have higher frequency. (Correct.)
- Ultraviolet rays have a lower frequency. (It is higher.)
- There is no difference in frequency. (It is higher.)
A: Ultraviolet waves have higher frequency.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: How does the direction of oscillation for the electric and magnetic field relate to each other in the propagation of electromagnetic radiation?
- They are both transverse and perpendicular to each other. (Correct)
- They are both transverse and parallel to each other. (Perpendicular.)
- The electric field is transverse and the magnetic field is longitudinal. (Transverse, perpendicular.)
- The electric field is longitudinal and the magnetic field is transverse. (Transverse and perpendicular.)
A: They are both transverse and perpendicular to each other.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Which color of light, red with a long wavelength or blue with a short wavelength is higher in energy?
- Blue (Correct.)
- Red (Energy is inversely related to wavelength of light.)
- Their energy is identical. (Energy is inversely related to wavelength of light.)
A: Blue
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Which behavior of light explains an upside down image being made by a pinhole camera?
- Light travels in straight lines. (Correct.)
- Angle of incidence equals the angle of reflection. (The pinhole does not reflect light.)
- Light refracting as it goes through the hole, much like a lens. (There is no change in material to refract.)
- Light diffracting through the small opening. (If light were diffracting, you would get a diffraction pattern.)
A: Light travels in straight lines.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: A light sensor is reading 500 lx when it is 1.0 meter away from a light source.  What will it be reading when it is 2.0 meters away?
- 125 lx (Correct.)
- 250 lx (It is a square relationship.)
- 1000 lx (The intensity goes down with distance.)
- 2000 lx (The intensity goes down with distance.)
- 500 lx (The intensity goes down with distance.)
A: 125 lx
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: How should the angle of incidence and reflection be measured?
- Both should be measured off of the normal. (Correct)
- Both should be measured off of the surface of the mirror. (The proper way is to use the normal.)
- Incidence is measured off the normal and reflection is measured off the mirror. (Both use the normal.)
- Incidence is measured off the mirror and reflection is measured off the normal. (Both use the normal.)
A: Both should be measured off of the normal.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: What happens to a ray of light as it goes from air into water?
- It gets bent towards the normal. (Correct.)
- It gets bent away from the normal. (That is what happens when light goes from a slow to a fast material.)
- Its incident and refracted angle are equal. (That is for reflection, not refraction.)
A: It gets bent towards the normal.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Glass has an index of refraction of 1.5 and diamond 2.4.  How does the speed of light compare in each material?
- The speed is lower in diamond. (Correct.)
- The speed is higher in diamond. (The greater the refractive index, the slower the light will go.)
- There is no difference between the two materials. (The reason the refractive index is different is the speed is different.)
A: The speed is lower in diamond.
If right: Your answer is correct.
If wrong: Your answer is incorrect.