Question 1

Situation 18.2
An erect object is 50 cm from a concave mirror of radius 60 cm.
-In Situation 18.2,the character of the image is:

Accepted Answer

The object is placed outside the focal point of the concave mirror, which is half the radius (30 cm). Therefore, the image formed is real and inverted.

Question 2

Situation 18.2
An erect object is 50 cm from a concave mirror of radius 60 cm.
-In Situation 18.2,the object is moved to a new position,such that the new lateral magnification is +2.5.The new object distance,in cm,is closest to:

Accepted Answer

The answer of Situation 18.2
An erect object is 50 cm...

Question 3

If an object is inside the focal point of a converging lens,this lens always produces a virtual image of that object;but if the object is outside the focal point,the lens always produces a real image.

Accepted Answer

When an object is inside the focal point of a converging lens, the light rays diverge after passing through the lens, and the image appears on the same side as the object, making it virtual. When the object is outside the focal point, the light rays converge to form a real image on the opposite side of the lens.

Question 4

What experiment could you quickly do to detect the difference between a real diamond and an identically shaped fake?

Accepted Answer

The answer of What experiment could you quickly do to...

Question 5

In the figure,in the investigation of a new type of optical fiber (index of refraction n = 1.26),a laser beam is incident on the flat end of a straight fiber in air.What is the maximum angle of incidence θ₁ if the beam is not to escape from the fiber?

Accepted Answer

The answer of  In the figure,in the investigation of...

Question 6

For both diverging and converging lenses,a ray parallel to the optical axis refracts through the far focal point.

Accepted Answer

For a converging lens, a ray parallel to the optical axis refracts through the focal point on the opposite side. For a diverging lens, it appears to diverge from the focal point on the same side.

Question 7

Situation 18.1
A tank holds a 1.44 m thick layer of oil that floats on a 0.96 m thick layer of brine.Both liquids are clear and do not intermix.Point O is at the bottom of the tank,on a vertical axis.The indices of refraction of the oil and the brine are 1.40 and 1.52,respectively.
-In Situation 18.1,a ray originating at O,crosses the brine-oil interface at a point 0.60 m from the axis.The ray continues and emerges into the air.The angle that the ray in the air makes with the vertical is closest to:

Accepted Answer

The ray in the air makes an angle of 48° with the vertical.This is because the ray undergoes refraction at the brine-oil interface and again at the oil-air interface. The net effect of these refractions is to bend the ray towards the normal at each interface. The angle of incidence at the brine-oil interface is 30°, and the angle of refraction is 20°. The angle of incidence at the oil-air interface is 20°, and the angle of refraction is 48°.

Question 8

Light goes from medium A into medium B.If you measure that the angle the rays make with the normal in A is less than the angle they make with the normal in B,then you can conclude that the refractive index of A is less than the refractive index of B.

Accepted Answer

When light enters a medium with a lower refractive index, it bends away from the normal, resulting in a larger angle with the normal in the second medium. Therefore, if the angle in medium A is less than in medium B, the refractive index of A is greater than that of B.

Question 9

Situation 18.2
An erect object is 50 cm from a concave mirror of radius 60 cm.
-In Situation 18.2,the lateral magnification of the image is closest to:

Accepted Answer

The answer of Situation 18.2
An erect object is 50 cm...

Question 10

A concave spherical mirror has a focal length f.The image of an object located at a distance s > f in front of the mirror is real and inverted.

Accepted Answer

For a concave spherical mirror, if the object is located at a distance greater than the focal length (s > f), the image formed is real and inverted. Therefore, the statement is true.

Question 11

Situation 18.1
A tank holds a 1.44 m thick layer of oil that floats on a 0.96 m thick layer of brine.Both liquids are clear and do not intermix.Point O is at the bottom of the tank,on a vertical axis.The indices of refraction of the oil and the brine are 1.40 and 1.52,respectively.
-In Situation 18.1,a ray originating at O reaches a point on the oil-air interface at the critical angle.The distance of this point from the axis is closest to:

Accepted Answer

The answer of Situation 18.1
A tank holds a 1.44 m...

Question 12

Situation 18.1
A tank holds a 1.44 m thick layer of oil that floats on a 0.96 m thick layer of brine.Both liquids are clear and do not intermix.Point O is at the bottom of the tank,on a vertical axis.The indices of refraction of the oil and the brine are 1.40 and 1.52,respectively.
-In Situation 18.1,a ray originating at O reaches a point on the brine-oil interface at the critical angle.The distance of this point from the axis is closest to:

Accepted Answer

The answer of Situation 18.1
A tank holds a 1.44 m...

Question 13

A single diverging lens always produces a virtual image of an object.

Accepted Answer

A single diverging lens always produces a virtual image of an object, meaning that the image appears to be on the opposite side of the lens compared to the object and cannot be projected onto a screen.

Question 14

In general,the more strongly curved a lens's surface,the lower its index of refraction.

Accepted Answer

The statement is actually false. The higher the curvature of a lens's surface, the higher its index of refraction. This is because a high curvature indicates a greater change in the direction of light passing through the lens, which requires a higher refractive index to achieve the necessary bending.

Question 15

Total internal reflection can occur only when light passes from a material of high refractive index to one of low refractive index,never the other way around.

Accepted Answer

Total internal reflection occurs when light passes from a material of high refractive index to one of low refractive index at an angle greater than the critical angle. This is because the light is unable to bend enough to pass through the boundary and is instead reflected back into the higher refractive index material. If light passes from a material of low refractive index to one of high refractive index, it bends towards the normal and there is no possibility of total internal reflection occurring.

Question 16

Situation 18.2
An erect object is 50 cm from a concave mirror of radius 60 cm.
-In Situation 18.2,the distance of the image from the mirror,in cm,is closest to:

Accepted Answer

Using the mirror formula,
1/v - 1/u = 1/f
where
v = distance of the image from the mirror
u = distance of the object from the mirror
f = focal length of the mirror

Since the mirror is concave, the focal length is negative:
f = -60 cm

Plugging in the given values:
1/v - 1/50 = 1/-60
1/v = -1/60 + 1/50
1/v = -5/3000 + 6/3000
1/v = 1/3000

v = 3000 cm = 30 m

Since the distance of the image is asked in cm, we need to convert the answer to cm:
30 m = 3000 cm

Therefore, the closest choice is D) 75 cm.

Question 17

A virtual image will not show up on a screen,and it cannot be photographed.

Accepted Answer

A virtual image cannot be projected onto a screen, but it can be photographed as it is visible to the eye.

Question 18

Describe the operation of a one-way mirror.Is there actually such an optical element?

Accepted Answer

The answer of Describe the operation of a one-way mirror.Is...

Question 19

The critical angle for two materials is the angle of incidence for which the incident light is not deflected as it passes from one of these materials into the other one.

Accepted Answer

The critical angle is the angle of incidence above which total internal reflection occurs, meaning the light does not pass into the other material but is instead reflected back into the original material.

Question 20

If a lens produces a magnification of 1/4,the image is 4 times a large as the object but is inverted.

Accepted Answer

A magnification of 1/4 means the image is 1/4 the size of the object, not 4 times larger. The image is smaller and inverted.

Quiz 18: Ray Optics

Situation 18.2 An erect object is 50 cm from a concave mirror of radius 60 cm. -In Situation 18.2,the character of the image is:

Situation 18.2 An erect object is 50 cm from a concave mirror of radius 60 cm. -In Situation 18.2,the object is moved to a new position,such that the new lateral magnification is +2.5.The new object distance,in cm,is closest to: