Question 1

A narrow light beam in vacuum contains light of two wavelengths, 480 nm and 700 nm. It strikes a flat piece of glass at an angle of incidence of 60.000°. The index of refraction of the glass is 1.4830 at 480 nm and 1.4760 at 700 nm. Determine the angle between the two wavelengths as the light travels in the glass.

Accepted Answer

The answer of A narrow light beam in vacuum contains...

Question 2

Which of following statements about the image formed by a single converging lens are true? (There could be more than one correct choice.)

Accepted Answer

A single converging lens can form both real and virtual images, and these images can be either upright or inverted depending on the object's position relative to the focal point. Therefore, none of the statements A, B, C, or D are always true.

Question 3

An object is placed on the left side of a thin lens, and the image of this object is formed on the left side of the lens. Which of the following statements must be true? (There could be more than one correct choice.)

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The answer of An object is placed on the left...

Question 4

If a object is placed between a convex lens and its focal point, the image formed is

Accepted Answer

When an object is placed between a convex lens and its focal point, the image formed is virtual and upright because the light rays diverge after passing through the lens, making it impossible for them to meet on the same side as the object. The lens then forms a virtual image on the same side as the object, which appears upright compared to the object.

Question 5

If the magnification of a mirror or lens is negative, it means that

Accepted Answer

A negative magnification indicates that the image formed by a mirror or lens is inverted relative to the object. It does not necessarily imply anything about the size of the image or its distance relative to the object or mirror/lens.

Question 6

An oil layer that is 5.0 cm thick is spread smoothly and evenly over the surface of water on a windless day. A light ray from the air above enters the oil at 45° with the normal and then goes into the water. What is the angle of refraction of this ray in the water? The index of refraction for the oil is 1.15, and for water it is 1.33.

Accepted Answer

Using Snell's Law, we can find the angle of refraction in the oil:
n1*sin(theta1) = n2*sin(theta2)
where n1 is the index of refraction of the first medium (air), n2 is the index of refraction of the second medium (oil), theta1 is the angle of incidence, and theta2 is the angle of refraction.

Plugging in the given values, we get:
1*sin(45) = 1.15*sin(theta2)
theta2 = arcsin(sin(45)/1.15) = 36.4° (rounded to one decimal place)

Next, we need to find the angle of refraction in the water.
n1*sin(theta1) = n2*sin(theta2)
where n1 is the index of refraction of the first medium (oil), n2 is the index of refraction of the second medium (water), theta1 is the angle of incidence (which is equal to the angle of refraction in the oil), and theta2 is the angle of refraction in the water.

Plugging in the given values, we get:
1.15*sin(36.4) = 1.33*sin(theta2)
theta2 = arcsin(1.15*sin(36.4)/1.33) = 31.7° (rounded to one decimal place)

Therefore, the answer is B) 32°, since this is the closest choice to our calculated angle of refraction in the water.

Question 7

Starting from very far away, an object is moved closer and closer to a diverging lens, eventually reaching the lens. What happens to its image formed by that lens? (There could be more than one correct choice.)

Accepted Answer

The answer of Starting from very far away, an object...

Question 8

The image formed by a single concave lens

Accepted Answer

A single concave lens always forms virtual images because the light rays diverge after passing through the lens, making it impossible for them to converge and form a real image on the opposite side of the lens.

Question 9

Is it possible to see a virtual image?

Accepted Answer

Virtual images can be "seen" by the eye because the rays that appear to come from the virtual image can be focused by the eye just like those from a real object. However, the rays do not actually emanate from the virtual image itself.

Question 10

Which of following statements about the image formed by a single diverging lens are true? (There could be more than one correct choice.)

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The answer of Which of following statements about the image...

Question 11

The index of refraction for a certain material is 1.399 for red light and 1.432 for blue light. Light containing both of these colors is traveling in vacuum and strikes a flat sheet of this material. Find the angle separating the two colors in the refracted light in the sheet if the angle of incidence is 60.00°.

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The answer of The index of refraction for a certain...

Question 12

An object is placed in front of a thin lens. Which statements are correct in describing the image formed by the lens? (There could be more than one correct choice.)

Accepted Answer

B) Real images formed by lenses are inverted due to the way light rays converge after passing through the lens. D) Concave lenses diverge light rays, making it impossible for the rays to converge on the same side as the object, thus always forming a virtual image.

Question 13

A ray of light (ray a) in air strikes a flat piece of glass at an angle of φ₀ = 84° with respect to the normal, as shown in the figure. The index of refraction of the glass is 1.5. What is the angle θ between the reflected ray (ray b) and refracted ray (ray c) rays?

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Question 14

A light beam having a wavelength of 470 nm in air is directed into glycerine at an angle of 75.0° with the normal in air. Glycerine has a refractive index of 1.47. (c = 3.0 × 10⁸ m/s) (a) What are the frequency and wavelength of the light in the glycerine? (b) What angle does the light beam make with the normal in the glycerine?

Accepted Answer

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Question 15

A thin beam of light enters a thick plastic sheet from air at an angle of 32.0° with the normal and continues in the sheet at an angle of 23.0° with the normal. What is the index of refraction of the plastic?

Accepted Answer

The index of refraction of the plastic can be found using Snell's Law, which is $n_1 \sin(\theta_1) = n_2 \sin(\theta_2)$, where $n_1$ and $n_2$ are the indices of refraction of the first and second medium respectively, and $\theta_1$ and $\theta_2$ are the angles of incidence and refraction respectively. Given that the light enters from air (with $n_1 = 1$) at an angle of $32.0^\circ$ and continues in the plastic at an angle of $23.0^\circ$, we can solve for $n_2$, the index of refraction of the plastic, as follows:$$1 \times \sin(32.0^\circ) = n_2 \times \sin(23.0^\circ)$$Solving for $n_2$ gives an index of refraction of approximately 1.36.

Question 16

Which statement about a single thin lens is correct?

Accepted Answer

Diverging lenses always produce images that are virtual and upright, regardless of the object's position relative to the lens.

Question 17

A thin laser beam traveling in air strikes the surface of a glass plate at 41.2° with the normal. In the plate, this beam makes an angle of 22.4° with the normal. What is the speed of light in this glass?(c = 3.0 × 10⁸ m/s)

Accepted Answer

The answer of A thin laser beam traveling in air...

Question 18

A plastic cube is immersed in water having an index of refraction of 1.33. A laser beam in the plastic strikes the interface at an angle of 14.5° with the normal in the plastic. In the water, this beam makes an angle of 21.8° with the normal. What is the speed of light in the plastic cube? (c = 3.0 × 10⁸ m/s)

Accepted Answer

The answer of A plastic cube is immersed in water...

Question 19

Starting from very far away, an object is moved closer and closer to a converging lens, eventually reaching the lens. What happens to its image formed by that lens? (There could be more than one correct choice.)

Accepted Answer

As the object moves closer and closer to the converging lens, the focal length of the lens effectively decreases, causing the image to move farther away from the lens. When the object is at the focal point, the image is formed at infinity, and is therefore real. As the object moves even closer to the lens, the image becomes virtual. Therefore, the image eventually changes from real to virtual.

Question 20

If a single lens forms a virtual image of an object, then

Accepted Answer

A virtual image can be formed by both converging and diverging lenses, so it is not necessary for the lens to be one or the other. The orientation of the image (whether it is upright or inverted) depends on the placement of the object and lens. Therefore, options A, B, and D can be eliminated. Option E is also incorrect because a virtual image is formed on the same side of the lens as the object, so it cannot be between the lens and its focal point.

Quiz 18: Ray Optics