Physics
1st Edition
ISBN: 9780133256925
Table of contents
Textbook solutions
All Solutions
Page 544: Lesson Check
Exercise 18
Step 1
1 of 2
$$
tt{An electron produces an electric field at all times when it starts oscillating the electric field will follow and produces a wave, this motion at the same time produces a wavy magnetic field, the two fields perpendicular to each other form the electromagnetic wave}
$$
tt{An electron produces an electric field at all times when it starts oscillating the electric field will follow and produces a wave, this motion at the same time produces a wavy magnetic field, the two fields perpendicular to each other form the electromagnetic wave}
$$
Result
2 of 2
$$
tt{electrons}
$$
tt{electrons}
$$
Exercise 19
Step 1
1 of 2
Ultraviolet wave has higher frequency than infrared, hence ultraviolet has smaller wavelength.
Result
2 of 2
Ultraviolet.
Exercise 20
Step 1
1 of 2
When red and blue light are mixed we will see magenta color.
Result
2 of 2
Magenta.
Exercise 21
Step 1
1 of 2
Cyan subtractive primary color corresponds to the combination of green and blue additive primary color.
Result
2 of 2
Cyan
Exercise 22
Step 1
1 of 4
We recall that when red, green, and blue light are added together, white light is produced. One third of the screen is red, one third white, and one third green.
Step 2
2 of 4
Red color dots are required for the red and white areas of the screen. So the number of red colors that are lit must be $text{textcolor{#c34632}{2,000,000}}$.
Step 3
3 of 4
Green color dots are required for the green and white areas of the screen. So the number of green colors that are lit must be $text{textcolor{#19804f}{2,000,000}}$.
Step 4
4 of 4
Blue color dots are only required for the white area of the screen. So the number of blue colors that are lit must be $text{textcolor{#4257b2}{1,000,000}}$.
Exercise 23
Step 1
1 of 1
The electromagnetic spectrum is classified into regions with increasing order of wavelength and each ranges of wavelengths correspond to a certain shade of color. The visible light is the part of the spectrum in which human eye is the most sensitive to and it has a frequency range of $4.3times 10^{14}$ Hz to $7.5times 10^{14}$ Hz. $textbf{Below the frequency of visible light is the infrared (IR) waves}$ which has a frequency that ranges from $10^{12}$ Hz to $4.3times 10^{14}$ Hz. $textbf{Above the frequency of visible light is the ultraviolet light}$ which has a frequency that ranges from $7.5times 10^{14}$ Hz to $10^{17}$ Hz. Finally, $textbf{the highest-frequency part of the EM spectrum is the gamma rays}$. It is highly energic rays which can be destructive to living cells.
Exercise 24
Step 1
1 of 3
Known:
$$
lambda=460 {rm nm=460times10^{-9} m}
$$
Unknown:
$$
f=?
$$
Solution:
$$
f=frac{c}{lambda}=frac{left(3times10^{8} {rm m/s}right)}{left(460times10^{-9} {rm m}right)}=6.52times10^{14} {rm Hz}
$$
Step 2
2 of 3
Period $T$ is
$$
T=frac{1}{f}=frac{1}{left(6.52times10^{14} {rm Hz}right)}=1.53times10^{-15} {rm s}
$$
Result
3 of 3
$6.52times10^{14} {rm Hz}$, $1.53times10^{-15} {rm s}$
Exercise 25
Step 1
1 of 2
Known:
$$
f=1.25times10^{9} {rm Hz}
$$
Unknown:
$$
lambda=?
$$
Solution:
$$
lambda=frac{c}{f}=frac{left(3times10^{8} {rm m/s}right)}{left(1.25times10^{9} {rm Hz}right)}=0.24 {rm m}
$$
Result
2 of 2
0.24 m
Exercise 26
Step 1
1 of 3
Known:
$$
lambda=9.0times10^{-6} {rm m}
$$
Unknown:
$$
f=?
$$
Solution
$$
f=frac{c}{lambda}=frac{left(3times10^{8} {rm m/s}right)}{left(9.0times10^{-6} {rm m}right)}=3.3times10^{13} {rm Hz}
$$
Step 2
2 of 3
This wave belongs to the infrared portion of the electromagnetic wave.
Result
3 of 3
(a) $3.3times10^{13} {rm Hz}$
(b) Infrared
unlock