Question 1

Which of the following best describes the behavior of light rays as they pass through a converging lens?

Accepted Answer

They refract toward the optical axis and converge at the focal point.

Question 2

A diverging lens is characterized by which of the following properties?

Accepted Answer

It is thinner in the center than at the edges and causes parallel rays to diverge.

Question 3

Which of the following is the correct thin-lens equation relating object distance $$s$$, image distance $$s'$$, and focal length $$f$$?

Accepted Answer

$$ \frac{1}{f} = \frac{1}{s} + \frac{1}{s'} $$

Question 4

A 4.0-cm-diameter flower is 200 cm from a 50-cm-focal-length converging lens. Where should the image detector be placed to record a focused image?

Accepted Answer

At 67 cm from the lens

Question 5

Which of the following statements about real images formed by a converging lens is correct?

Accepted Answer

They are always inverted and can be projected onto a screen.

Question 6

A virtual image formed by a lens has which of the following properties?

Accepted Answer

It is always upright and cannot be projected onto a screen.

Question 7

For a diverging lens, which of the following is true about the focal length $$f$$ and the image distance $$s'$$?

Accepted Answer

$$f is $$negative and $$s' is $$negative for virtual images.

Question 8

A magnifying glass with a focal length of 6.0 cm is held 4.0 cm from an object. What is the magnification of the image?

Accepted Answer

$$ m = +2 $$

Question 9

Which of the following best explains why a convex (diverging) mirror is used as a passenger-side rearview mirror in cars?

Accepted Answer

It produces a smaller image, allowing a wider field of view.

Question 10

A concave mirror has a focal length of 40 cm. An object is placed 60 cm from the mirror. Where is the image formed?

Accepted Answer

At 120 cm from the mirror

Question 11

Which of the following is the correct sign convention for the focal length $$f of a $$lens or mirror?

Accepted Answer

$$f is $$positive for converging lenses and mirrors, negative for diverging.

Question 12

A ray passing through the center of a thin lens will:

Accepted Answer

Pass straight through without bending.

Question 13

Which of the following is true for the magnification $$m of a $$lens or mirror?

Accepted Answer

$$ m = \frac{h'}{h} = -\frac{s'}{s} $$

Question 14

A student uses a lens to focus sunlight to a point and start a fire. What type of lens is required?

Accepted Answer

A converging lens

Question 15

If an object is placed inside the focal length of a converging lens, what type of image is formed?

Accepted Answer

A virtual, upright image

Question 16

Which of the following best describes the image formed by a diverging lens for any object position?

Accepted Answer

Virtual, upright, and smaller than the object

Question 17

A stamp collector uses a magnifying lens 2.0 cm above a stamp and observes a magnification of 4. What is the focal length of the lens?

Accepted Answer

2.7 cm

Question 18

Which of the following is NOT a correct special ray for ray tracing a converging lens?

Accepted Answer

A ray parallel to the optical axis refracts away from the optical axis.

Question 19

Which of the following statements about the image formed by a convex (diverging) mirror is correct?

Accepted Answer

The image is virtual, upright, and smaller than the object.

Question 20

A ray of light passes from air into glass at an angle. According to Snell’s law, what happens to the ray?

Accepted Answer

It bends toward the normal because glass has a higher index of refraction.

Thin Lenses and Spherical Mirrors: Ray Tracing and Image Formation

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