Reading:

Cutnell and Johnson, Chapters 24 and 25.

Problems for Review:

Reviewing these problems gives you good exposure to this week's main topics, in practice. All are worked in the Student Study Guide [SSG] or Student Solutions Manual [SSM]; solutions are posted on our website http://www.physics.emory.edu/Classes/142-003.html , for those without these texts.

Conceptual:

MCAT review problem, [SSG] p 482.

Quantitative:

Chapter 24, problems 1, 9, 27, 37, 45.
Chapter 25, problems 1, 5, 13, 17, 21, 29.

Problems to Hand In:

Conceptual:

Questions 1 through 10 refer to the situation below:

$\parbox{2in}{ An electromagnetic wave travels in the $-z$\ direction... ...e of 12 N/C at $t=0$. The frequency of the wave is $1.0\ \times\ 10^{16}$\ Hz.}$

1. What is the wavelength of this electromagnetic wave?
   1. 0.33 nm
   2. 3.3 nm
   3. 20 nm
   4. 30 nm
   5. 40 nm

2. To which region of the electromagnetic spectrum does this electromagnetic wave belong?
   1. X-rays
   2. gamma rays
   3. ultraviolet radiation
   4. infrared radiation
   5. radio waves

3. What is the associated magnetic field $\vec { B}$ at point O at time $t=0$?
   1. $4.0\ \times\ 10^{-8}\ {\rm T}$, in the $+y$ direction
   2. $4.0\ \times\ 10^{-8}\ {\rm T}$, in the $-y$ direction
   3. $4.0\ \times\ 10^{-8}\ {\rm T}$, in the $+z$ direction
   4. $2.5\ \times\ 10^{7}\ {\rm T}$, in the $-y$ direction
   5. $2.5\ \times\ 10^{7}\ {\rm T}$, in the $-z$ direction

4. What is the electric field $\vec { E}$ at point O at time $t=5.0\ \times\ 10^{-17} s$?
   1. 12 N/C, in the $+x$ direction
   2. 6 N/C, in the $+x$ direction
   3. 12 N/C, in the $-x$ direction
   4. 6 N/C, in the $-x$ direction
   5. zero

5. What is the direction of polarization for this electromagnetic wave?
   1. the $x$ axis
   2. the $y$ axis
   3. the $z$ axis
   4. $45^o$ counterclockwise from the $x$ axis
   5. cannot be determined from the information given

6. Treating this electromagnetic wave as a light ray, in which direction is the light ray traveling?
   1. the positive $x$ direction
   2. the negative $x$ direction
   3. the positive $y$ direction
   4. the negative $y$ direction
   5. the negative $z$ direction

7. It is wished to reduce the intensity of this light ray by a factor of 4. In which of the orientations below should a polaroid filter be placed?

   

8. A polaroid filter with polarizing axis $45^o$ counterclockwise from the $x$ axis is inserted in the path of the light ray just before it reaches the page. What, then, is the new electric field $\vec { E}$ at O at time $t=0$?
   1. 12 N/C, in the direction $45^o$ counterclockwise from the $+x$ direction
   2. 8.5 N/C, in the $+x$ direction
   3. 8.5 N/C, in the direction $45^o$ counterclockwise from the $+x$ direction
   4. 6 N/C, in the $+x$ direction
   5. 6 N/C, in the direction $45^o$ counterclockwise from the $+x$ direction

9. The light ray above emerges from an object and is incident on a mirror. In which of the following cases is the image produced VIRTUAL? Circle ALL correct answers.
   1. The mirror is plane.
   2. The mirror is convex.
   3. The mirror is concave, and the light ray originates inside the mirror's focal length.
   4. The mirror is concave, and the light ray originates outside the mirror's focal length.

10. The light ray above emerges from an object and is incident on a mirror. In which of the following cases is the image produced INVERTED? Circle ALL correct answers.
    1. The mirror is plane.
    2. The mirror is convex.
    3. The mirror is concave, and the light ray originates inside the mirror's focal length.
    4. The mirror is concave, and the light ray originates outside the mirror's focal length.

Quantitative:

Chapter 24, problems 26, 35, 40, 42.
Chapter 25, problems 12, 24, 26, 34.