Conceptual Questions:
1. In order of increasing frequency, which of the following is correct?
a. visible, radio,ultraviolet and X-ray
b. infrared, visible, ultraviolet and gamma
c. visible, gamma, ultraviolet and X-ray
d. infrared, X-ray, visible and gamma
2. The electric field, E, in an electromagnetic wave is oriented in what direction with respect to its associated magnetic field, B?
a. E is parallel to B.
b. E is anti-parallel to B.
c. E is perpendicular to B.
d. E is at a 45ø angle to B.
3. How is the direction of propagation of an electromagnetic wave oriented relative to the associated E and B fields?
a. It is parallel to both E and B.
b. It is perpendicular to both E and B.
c. It is parallel to E, perpendicular to B.
d. It is parallel to B. perpendicular to E.
4. Temperature variations of different parts of a person's body can be detected by analyzing the emission pattern of which type of electromagnetic radiation?
a. microwave
b. infrared
c. ultraviolet
d. X-rays
5. Approximately what is the shortest (or longest) wavelength of EM radiation visible to the normal human eye?
a. 200 nm
b. 400 nm
c. 500 nm
d. 700 nm
6. Microwave ovens emit a frequency intended to be in resonance with which of the following?
a. The oscillation frequency of water molecules.
b. The size of the oven compartment.
c. The frequency of the metal lining of the oven.
d. The oscillation frequency of food molecules.
7. Maxwell developed his theory of electromagnetism by combining previous discoveries. He added his own original hypothesis that:
a. electrical charges produce electrical fields.
b. moving electrical charges produce magnetic fields.
c. changing electrical fields produce magnetic fields.
d. changing magnetic fields produce electrical fields.
Numerical Problems: answers link to a help page.
1. An electromagnetic wave with a peak electric field component of 120 N/C has what associated peak magnetic field value?
2. What is the wavelength of 100 MHz television EM-waves?
3. What is the maximum value of the electric field E at 1 meter from a 100-watt lightbulb radiating in all directions? (mo = 4p x10-7 T*m/A)