Light and optics
Which of the following means that an image is located in front of a mirror?
+di
A beam of light passes from air into water. Which of the following statements is true?
- The frequency of the light remains constant -
A 20 cm wide object seen through an optical device appears inverted and 60 cm wide. What is the magnification of the optical device?
-3
The index of refraction in water is 1.330 for red light (λ = 700 nm), and 1.345 for violet light (λ = 400 nm). How much longer will it take violet light than red to cross 0.630 m of water?
0.040 ns
A 90. cm tall object seen through an optical device appears 80. cm tall. What is the magnification of the optical device?
0.89
A light ray in glass (n = 1.50) strikes an unknown material with an angle of incidence of 45.0°. The angle of refraction in this material is measured to be 67.0°. What is the index of refraction of this material?
1.15
An object is placed 20.0 m away from a converging lens that has a focal length of 1.00 m. At approximately what distance from the lens is the image formed?
1.1m
The frequency of a wave is 5.1 • 10^14 Hz. The speed of a wave in a certain medium is 2.1 • 10^8 m/s. What is the index of refraction of the medium?
1.4
The speed of light through a piece of plastic is approximately 2.0 • 108 m/s. What is the index of refraction of this plastic?
1.5
Light takes 8.50 minutes to go from the Sun to the Earth. So how far away is the Sun?
1.53•10^11 m
The magnification factor of an optical device is 2.9. If the size of an image is 4.9 cm, what is the size of the real object?
1.7 cm
What is the period of a 60. hertz electromagnetic wave traveling at the speed of light?
1.7•10^-2 seconds
What is the speed of a ray of light in flint glass (n = 1.61)?
1.86 • 10^8m/s
An object is 15.00 cm from a convex lens that has a focal length of 6.00 cm. What distance is the image from the lens?
10.0cm
The speed of light in a piece of glass is 1.5 • 108 m/s. What is the index of refraction of the glass?
2.0
How much time does it take light from a flash camera to reach a subject 6.0 meters across a room?
2.0 • 10^-8 seconds
You and a friend are looking in a large, flat mirror against a wall. Your friend is 0.80 m away from the mirror and you are 0.50 m directly behind her. How far are you from the image of your friend in the mirror?
2.1 m
A beam of light enters the flat surface of a diamond from air (n = 1.00) at an angle of 30° from the normal. The angle of refraction in the diamond is measured to be 12° from the normal. Determine the index of refraction for the diamond.
2.5
The speed of a ray of light traveling through a substance having an absolute index of refraction of 1.1 is
2.7 • 10^8 m/s
An object is placed 30. m away from a converging lens and the image appears at a distance of 70. m from the lens. What is the focal length of the lens?
21m
A light ray traveling through air (n = 1.00) is incident on a pool of water (n = 1.33). If the light has an angle of incidence of 30.6°, what is the angle of refraction in the water?
22.5
Ami wants to project a real image of an object magnified by a factor of 4.3 onto a screen using a convex lens with a focal length of 19 cm. How far should she place the object from the lens?
23cm
A concave mirror has a focal length of 15. cm. A 5.0 cm tall candle is placed at a distance of 40.0 cm in front of the mirror. Determine the image distance.
24 cm
A ray of light in air (n = 1.00) enters water (n = 1.33) at an angle of 51°. What is the angle of refraction?
36
Violet light has a frequency of 7.5 • 1014 Hz. The wavelength of violet light is most nearly
4.0 • 10^-7 m
If a curved mirror has a focal length of 20 cm, what is its radius of curvature?
40cm
A ray of light strikes a flat mirror at an angle of incidence of 49.0º. What is the angle of reflection?
49.0º
What is the frequency of light with a wavelength of 570 nm?
5.3 • 10^14 Hz
What is the wavelength of light which has a frequency of 5.4 • 10^14Hz?
5.6 • 10-7 m
A 29 cm wide image is seen through a compound system with a magnification of 5.0. What is the width of the object?
5.8cm
Sally's face is 54 cm in front of a plane mirror. Where is the image of Sally's face?
54 cm behind the mirror
An object is located 20.0 cm from a convex lens. The lens forms a real image at a distance of 10.0 cm. What is the focal length of this lens?
6.67cm
Which statement about images is correct?
A virtual image cannot be formed on a screen.
Polarization is:
A way of aligning the direction of light wave vibration by blocking some of the waves
Which of the following was used to argue that light behaves as a particle?
All of the above.
You decide to plant an herb garden in a small planter box in your kitchen. As there are no windows in your kitchen you decide to set up a light above your herbs to provide energy for photosynthesis. When choosing a light for your green herbs, which color of light is the least important that the bulb is able to produce?
Green light
A man is standing 1.9 m in front of a flat mirror and facing the mirror. How far away from him does his image appear to be located?
His image is located 3.8 m in front of him.
A device that uses refraction to bend light to form an image is a:
Lens
What property of light explains the formation of shadows?
Light travels in straight lines.
Mixing red and blue light will produce what color light?
Magenta
Which phenomenon best explains the path of light through the lens?
Refraction
When the sun is low on the horizon at sunset, it appears redder in color, the best explanation for this is that the atmosphere
Scatters the shorter wavelength, blue and green light
The relationship between the angles of incidence and refraction for a ray of light as it passes through a boundary between two different media is given by
Snells law
On a bright and sunny day, a pedestrian notices his faint image in a shop window. Why did he see his image in the glass?
Some of the light was reflected off of the glass.
During a thunderstorm, why can you see lightning before you can hear thunder?
Sound travels slower than light.
When describing image formation for a plane mirrors, what is an important rule to remember about light rays?
The angle when it leaves the mirror is the same as the angle when it hits.
Two beams of light, red and blue, enter a prism as shown above. Which of the following statements is true concerning the light as it passes through the prism?
The blue light will bend more than the red light, since the blue light has a shorter wavelength
A variable-frequency light source emits a series of photons. As the frequency of the photon increases, what happens to the energy and wavelength of the photon?
The energy increases and the wavelength decreases.
The difference between visible light and X rays is that
The frequency of x-rays is greater
Which of the following is true of a diverging lens?
The lens is thinner in the center than on the edges.
Which of the following statements is true about both sound waves and light (electromagnetic waves)?
The shorter the wavelength, the higher the frequency
Which type of electromagnetic radiation is associated with an increased risk of skin cancer?
UV light
The Moon is typically about 384,000 km from Earth. Very roughly, how long would it take light to travel from Earth to the Moon?
a second
Which of the following provides evidence that light can behave like a wave?
all of these
A plane mirror will produce a virtual image
at all distance from the mirror.
The image formed in a plane mirror is
at the same distance behind the mirror as the object is in front of the mirror.
If you are wearing a red shirt, but then you go into a dark room that is only lit by a faint green light, then what color will your shirt seem to be?
black
White light from the sun appears yellow to you because what color of light has been refracted out (through a process called dispersion) by our atmosphere?
blue
An object is placed 4 m away from a converging lens that has a focal length of 6 m. Which of the following statements is true?
c. The image is upright with magnification m > 1. d. The image is inverted with magnification m > 1.
Which of the following is the best description of the optical axis of a spherical mirror?
c. a line passing through both the focal point and the center of curvature
An incident ray traveling parallel to a concave spherical mirror's principal axis strikes the mirror's surface. In what direction does it reflect?
c. along a line that passes through the intersection of the mirror and the principal axis d. along a line that passes through the focal point
An object is placed 5 cm away from an optical device. The image is magnified and has the same orientation as the object. The optical device could be a
concave mirror convex lens
Mixing green and blue light will produce what color light?
cyan
A student places a piece of glass over a tank of water. What happens to the speed of a light ray that shines from air through glass into the water?
decreases in glass, then increases in water.
A ray of light passes through air (n = 1.00), glass (n = 1.50), and then water (n = 1.33). Select the answer that best describes what happens to the velocity of the ray as it passes from air into glass and then out of the glass into water.
decreases, then increases
Which phenomenon provides evidence that light has a wave nature?
diffraction of light passing through a narrow opening
Radio waves are propagated through the interaction what two fields?
electric and magnetic
Light is a type of _______ wave.
electromagnetic
Which type of electromagnetic radiation is used to kill cancer cells?
gamma rays
Compared to a photon of red light, a photon of blue light has a...
greater energy
If you are wearing a white shirt, but then you go into a dark room that is only lit by a faint green light, then what color will your shirt seem to be?
green
What color of light is not absorbed by a green object?
green
Electromagnetic waves that are just below the visible spectrum of light are called
infrared
Red light is passed through two narrow slits and forms a pattern of bright and dark lines on a screen. The phenomenon primarily responsible for this pattern is
interference
On a sunny day, black asphalt that receives direct sunlight can become quite warm. This occurs because much of the energy of the electromagnetic (or light) waves striking the asphalt
is absorbed.
Which of the following is NOT a compound optical system?
magnifying glass
Electromagnetic waves that are low energy and have extremely long wavelengths are examples of..
radio waves
Which of the following lists the electromagnetic waves from longest wavelength to shortest wavelength
radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, gamma rays
A candle is placed on the principal axis of a concave mirror at a distance of 20 cm from the mirror. The focal length of the mirror is 10 cm. The image formed will be
real and inverted
A candle is placed on the principal axis of a convex lens at a distance of 30 cm from the lens. The focal length of the lens is 10 cm. The image formed will be
real and inverted
The lens in your eye forms an image on the retina which is:
real and inverted
Skiers will often wear sunglasses because much of the sunlight that strikes snow is
reflected
The ray of light that bounces off a mirror is the
reflected ray
The ray of light that bounces off a mirror is the:
reflected ray
When a DVD is read, laser light touches the DVD surface and is then measured by a sensor. What allows light to return to the sensor after striking the DVD surface?
reflection
A lens forms an image primarily due to the phenomenon of
refraction
When trying to spear a fish in water, a person needs to take into account the way light bends as it moves from water into air. The bending of light as it passes from one medium into another is known as
refraction
A microwave and an x-ray are traveling in a vacuum. Compared to the wavelength and period of the microwave, the x-ray has a wavelength that is
shorter and a period that is shorter
Radio waves and gamma waves traveling through space have the same
speed
Which quantity is equivalent to the product of the absolute index of refraction of water No and the speed of light in water?
speed of light in a vacuum
Scientists can tell that the universe is expanding because light from other galaxies is shifted towards the red end of the visible spectrum (called the red-shift). This shift in the frequency of light due to the relative motion of one galaxy to another is caused by which of the following:
the Doppler Effect
The color of light is determined by ____ of the light wave
the frequency
The difference between visible light and X rays is that...
the frequency of X rays is greater
What happens to the frequency and the speed of an electromagnetic wave as it passes from air into glass?
the frequency remains the same and the speed decreases.
The image of an object in a plane (flat) mirror is always
the same size as the object
A candle is placed on the principal axis of a concave mirror at a distance of 10 cm from the mirror. The focal length of the mirror is 20 cm. The image formed will be
virtual and upright
Electromagnetic waves that can pass through skin and have short wavelengths.
x-rays
Mixing red and green light will produce what color light?
yellow
Which of the following is a primary color of pigment?
yellow
Which of the following is not a primary color of light?
yellow