Question 1

A contact lens is made of plastic with an index of refraction of 1.50. The lens has an outer radius of curvature of +2.0 cm and an inner radius of curvature of +2.5 cm. What are the focal length and the power of the lens?

Accepted Answer

The answer of A contact lens is made of plastic...

Question 2

A layer of ethyl alcohol (n = 1.361) is on top of water (n = 1.333). To the nearest degree, at what angle relative to the normal to the interface of the two liquids is light totally reflected?

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Question 3

An aquarium contains a 5-cm layer of water (n = 1.333) floating on top of carbon tetrachloride (n = 1.461). If the angle of incidence into the water from the carbon tetrachloride is 20°, what is the angle of refraction into the air?

Accepted Answer

The answer of An aquarium contains a 5-cm layer of...

Question 4

A magnifying glass has a convex lens of focal length 15 cm. At what distance from a postage stamp should you hold this lens to get a magnification of +2.0?

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Question 5

A diver shines light up to the surface of a flat glass-bottomed boat at an angle of 30° relative to the normal. If the index of refraction of water and glass are 1.33 and 1.5, respectively, at what angle (in degrees) does the light leave the glass (relative to its normal)?

Accepted Answer

Using Snell's Law, we can find the angle at which the light is refracted in the glass:

n1*sin(theta1) = n2*sin(theta2)

where n1 and n2 are the indices of refraction of the initial and final mediums, respectively, and theta1 and theta2 are the angles of incidence and refraction, respectively, relative to the normal.

Plugging in the given values:

1.33*sin(30) = 1.5*sin(theta2)

sin(theta2) = (1.33*sin(30))/1.5 = 0.396

theta2 = arcsin(0.396) = 23.6°

So the light leaves the glass at an angle of 23.6° relative to its normal.

Therefore, the best choice is C, 42 degrees.

Question 6

An object is placed 25 cm in front of a lens of focal length 20 cm. 60 cm past the first lens is a second lens of focal length 25 cm. What is the resulting magnification of the object in this setup?

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Question 7

An aquarium contains a 5-cm layer of water (n = 1.33) floating on top of carbon tetrachloride (n = 1.461). If the angle of incidence into the water from the air is 30°, what is the angle of refraction into the carbon tetrachloride?

Accepted Answer

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Question 8

Light strikes a diamond (n = 2.42) immersed in glycerin (n = 1.473) at an angle of 60° relative to the normal to the surface. What is the angle of refraction?

Accepted Answer

Using Snell's Law: 
n1 sin(theta1) = n2 sin(theta2)

Here, 
n1 (incident medium) = 1 (air)
n2 (refracted medium) = 1.473 (glycerin)
theta1 (angle of incidence) = 60 degrees

Substituting the values,
1 x sin 60 = 1.473 x sin (theta2)
sin (theta2) = (1/1.473) x sin 60
sin (theta2) = 0.6726
theta2 = sin^-1 (0.6726)
theta2 = 42° (approx.)

Therefore, the angle of refraction is 42°, which is closest to choice C (32°).

Question 9

Light strikes a diamond (n = 2.42) at an angle of 60° relative to the normal to the surface. What is the angle of refraction?

Accepted Answer

Using Snell's Law, n1*sin(theta1) = n2*sin(theta2), where n1 = 1 (for air), theta1 = 60°, and n2 = 2.42 (for diamond). Solving for theta2 gives an angle of refraction of approximately 21°.

Question 10

A soda straw is stuck into water at an angle of 36° to the vertical. Looking straight down, what does the angle of the submerged portion of the straw to the vertical appear to be?

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The answer of A soda straw is stuck into water...

Question 11

A light ray is incident on the surface of water (n = 1.33) at an angle of 60° relative to the normal to the surface. The angle of the reflected wave is

Accepted Answer

According to the law of reflection, the angle of incidence is equal to the angle of reflection. Since the light ray is incident at an angle of 60° relative to the normal, the angle of the reflected wave will also be 60°.

Question 12

The speed of light changes when it goes from ethyl alcohol (n = 1.36) to carbon tetrachloride (n = 1.46). The ratio of the speed in carbon tetrachloride to the speed in ethyl alcohol, v₂/v₁, is

Accepted Answer

The answer of The speed of light changes when it...

Question 13

A diver shines an underwater searchlight at the surface of a pond (n = 1.33). At what angle (relative to the surface) will the light be totally reflected?

Accepted Answer

The critical angle for total internal reflection can be calculated using the formula:
sinθc = 1/n

where θc is the critical angle and n is the refractive index of the medium (in this case, water with n = 1.33). 
Substituting the values, we get:
sinθc = 1/1.33 
θc = sin-1(0.751) 
θc ≈ 41.2°

Therefore, the light will be totally reflected at an angle of 41.2° relative to the surface.

Question 14

Light is refracted through a diamond. If the angle of incidence is 30°, and the angle of refraction is 12°, what is the index of refraction?

Accepted Answer

The index of refraction can be calculated using Snell's law: n=sin(i)/sin(r), where i is the angle of incidence and r is the angle of refraction. Plugging in the given values, we get n=sin(30°)/sin(12°) ≈ 2.4. Therefore, the best choice is B) 2.4.

Question 15

A person in a boat sees a fish in the water (n = 1.33), the light rays making an angle of 40° relative to the water's surface. What is the true angle (in degrees) relative to the water's surface of the same rays when beneath the surface?

Accepted Answer

Using Snell's Law, we can find the angle of refraction:

n1 * sin(theta1) = n2 * sin(theta2)

Assuming n1 is the index of refraction of air and n2 is the index of refraction of water (1.33), we get:

1 * sin(40°) = 1.33 * sin(theta2)

sin(theta2) = 0.479

theta2 = sin^-1(0.479) = 29.3°

Therefore, the true angle relative to the water's surface is:

90° - 29.3° = 60.7° ≈ 61°

The best choice is D.

Question 16

An object is placed 25 cm in front of a lens of focal length 20 cm. 60 cm past the first lens is a second lens of focal length 25 cm. How far past the 25-cm lens does the final image form?

Accepted Answer

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Question 17

A fish is 80 cm below the surface of a pond. What is the apparent depth (in cm) when viewed from a position almost directly above the fish? (For water, n = 1.33.)

Accepted Answer

The apparent depth of an object submerged in a medium with refractive index n can be calculated using the formula: apparent depth = real depth / n. In this case, the real depth is 80 cm and the refractive index of water is 1.33. Therefore, the apparent depth = 80 / 1.33 = 60 cm. Thus, the best choice is B.

Question 18

A light ray whose frequency is 6.00 × 1014 Hz in vacuum is incident on water (n = 1.33). The wavelength of the light after it enters the water is (in nm)

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Question 19

A person looks horizontally at the edge of a swimming pool. If its length is 5 m, and the pool is filled to the surface, to what depth (in m) could the observer see? (n for water is 1.33.)

Accepted Answer

The depth that the observer can see is given by the formula: depth = length/sin(angle of incidence). If we assume that the person is standing at the edge of the pool, the angle of incidence is 90 degrees. Therefore, depth = 5/sin(90) = 5/1 = 5 m. However, since the pool is filled with water, we need to take into account the refractive index of water. The formula for the angle of refraction is given by: sin(angle of refraction) = sin(angle of incidence)/n. Substituting the values, we get: sin(angle of refraction) = sin(90)/1.33 = 0.7519. Therefore, the angle of refraction is about 48.75 degrees. The angle between the line of sight and the water surface is the angle of incidence plus the angle of refraction, which is about 138.75 degrees. Therefore, the depth that the observer can see is given by: depth = 5/sin(138.75) = 4.4 m (approximately). Hence, the correct answer is B.

Question 20

Suppose an object is placed 6.0 cm in front of a lens that has a focal length of 4.0 cm. Where is the image located? What are the magnification and the character of the image?

Accepted Answer

The answer of Suppose an object is placed 6.0 cm...

Quiz 38: Refraction and Images Formed by Refraction

A contact lens is made of plastic with an index of refraction of 1.50. The lens has an outer radius of curvature of +2.0 cm and an inner radius of curvature of +2.5 cm. What are the focal length and the power of the lens?

A layer of ethyl alcohol (n = 1.361) is on top of water (n = 1.333) . To the nearest degree, at what angle relative to the normal to the interface of the two liquids is light totally reflected?

An aquarium contains a 5-cm layer of water (n = 1.333) floating on top of carbon tetrachloride (n = 1.461) . If the angle of incidence into the water from the carbon tetrachloride is 20°, what is the angle of refraction into the air?

A magnifying glass has a convex lens of focal length 15 cm. At what distance from a postage stamp should you hold this lens to get a magnification of +2.0?

A diver shines light up to the surface of a flat glass-bottomed boat at an angle of 30° relative to the normal. If the index of refraction of water and glass are 1.33 and 1.5, respectively, at what angle (in degrees) does the light leave the glass (relative to its normal) ?

An object is placed 25 cm in front of a lens of focal length 20 cm. 60 cm past the first lens is a second lens of focal length 25 cm. What is the resulting magnification of the object in this setup?

An aquarium contains a 5-cm layer of water (n = 1.33) floating on top of carbon tetrachloride (n = 1.461) . If the angle of incidence into the water from the air is 30°, what is the angle of refraction into the carbon tetrachloride?

Light strikes a diamond (n = 2.42) immersed in glycerin (n = 1.473) at an angle of 60° relative to the normal to the surface. What is the angle of refraction?

Light strikes a diamond (n = 2.42) at an angle of 60° relative to the normal to the surface. What is the angle of refraction?

A soda straw is stuck into water at an angle of 36° to the vertical. Looking straight down, what does the angle of the submerged portion of the straw to the vertical appear to be?

A light ray is incident on the surface of water (n = 1.33) at an angle of 60° relative to the normal to the surface. The angle of the reflected wave is

The speed of light changes when it goes from ethyl alcohol (n = 1.36) to carbon tetrachloride (n = 1.46) . The ratio of the speed in carbon tetrachloride to the speed in ethyl alcohol, v₂/v₁, is

A diver shines an underwater searchlight at the surface of a pond (n = 1.33) . At what angle (relative to the surface) will the light be totally reflected?

Light is refracted through a diamond. If the angle of incidence is 30°, and the angle of refraction is 12°, what is the index of refraction?

A person in a boat sees a fish in the water (n = 1.33) , the light rays making an angle of 40° relative to the water's surface. What is the true angle (in degrees) relative to the water's surface of the same rays when beneath the surface?

An object is placed 25 cm in front of a lens of focal length 20 cm. 60 cm past the first lens is a second lens of focal length 25 cm. How far past the 25-cm lens does the final image form?

A fish is 80 cm below the surface of a pond. What is the apparent depth (in cm) when viewed from a position almost directly above the fish? (For water, n = 1.33.)

A light ray whose frequency is 6.00 × 1014 Hz in vacuum is incident on water (n = 1.33) . The wavelength of the light after it enters the water is (in nm)

A person looks horizontally at the edge of a swimming pool. If its length is 5 m, and the pool is filled to the surface, to what depth (in m) could the observer see? (n for water is 1.33.)

Suppose an object is placed 6.0 cm in front of a lens that has a focal length of 4.0 cm. Where is the image located? What are the magnification and the character of the image?

Quiz 38: Refraction and Images Formed by Refraction

A contact lens is made of plastic with an index of refraction of 1.50. The lens has an outer radius of curvature of +2.0 cm and an inner radius of curvature of +2.5 cm. What are the focal length and the power of the lens?

A layer of ethyl alcohol (n = 1.361) is on top of water (n = 1.333) . To the nearest degree, at what angle relative to the normal to the interface of the two liquids is light totally reflected?

An aquarium contains a 5-cm layer of water (n = 1.333) floating on top of carbon tetrachloride (n = 1.461) . If the angle of incidence into the water from the carbon tetrachloride is 20°, what is the angle of refraction into the air?

A magnifying glass has a convex lens of focal length 15 cm. At what distance from a postage stamp should you hold this lens to get a magnification of +2.0?

A diver shines light up to the surface of a flat glass-bottomed boat at an angle of 30° relative to the normal. If the index of refraction of water and glass are 1.33 and 1.5, respectively, at what angle (in degrees) does the light leave the glass (relative to its normal) ?

An object is placed 25 cm in front of a lens of focal length 20 cm. 60 cm past the first lens is a second lens of focal length 25 cm. What is the resulting magnification of the object in this setup?

An aquarium contains a 5-cm layer of water (n = 1.33) floating on top of carbon tetrachloride (n = 1.461) . If the angle of incidence into the water from the air is 30°, what is the angle of refraction into the carbon tetrachloride?

Light strikes a diamond (n = 2.42) immersed in glycerin (n = 1.473) at an angle of 60° relative to the normal to the surface. What is the angle of refraction?

Light strikes a diamond (n = 2.42) at an angle of 60° relative to the normal to the surface. What is the angle of refraction?

A soda straw is stuck into water at an angle of 36° to the vertical. Looking straight down, what does the angle of the submerged portion of the straw to the vertical appear to be?

A light ray is incident on the surface of water (n = 1.33) at an angle of 60° relative to the normal to the surface. The angle of the reflected wave is

The speed of light changes when it goes from ethyl alcohol (n = 1.36) to carbon tetrachloride (n = 1.46) . The ratio of the speed in carbon tetrachloride to the speed in ethyl alcohol, v2/v1, is

A diver shines an underwater searchlight at the surface of a pond (n = 1.33) . At what angle (relative to the surface) will the light be totally reflected?

Light is refracted through a diamond. If the angle of incidence is 30°, and the angle of refraction is 12°, what is the index of refraction?

A person in a boat sees a fish in the water (n = 1.33) , the light rays making an angle of 40° relative to the water's surface. What is the true angle (in degrees) relative to the water's surface of the same rays when beneath the surface?

An object is placed 25 cm in front of a lens of focal length 20 cm. 60 cm past the first lens is a second lens of focal length 25 cm. How far past the 25-cm lens does the final image form?

A fish is 80 cm below the surface of a pond. What is the apparent depth (in cm) when viewed from a position almost directly above the fish? (For water, n = 1.33.)

A light ray whose frequency is 6.00 × 1014 Hz in vacuum is incident on water (n = 1.33) . The wavelength of the light after it enters the water is (in nm)

A person looks horizontally at the edge of a swimming pool. If its length is 5 m, and the pool is filled to the surface, to what depth (in m) could the observer see? (n for water is 1.33.)

Suppose an object is placed 6.0 cm in front of a lens that has a focal length of 4.0 cm. Where is the image located? What are the magnification and the character of the image?

The speed of light changes when it goes from ethyl alcohol (n = 1.36) to carbon tetrachloride (n = 1.46) . The ratio of the speed in carbon tetrachloride to the speed in ethyl alcohol, v₂/v₁, is