物理透鏡 DSE、CE 選擇題（第 2 頁）

11.

Which of the following examples illustrate(s) a real image ?

(1)a fish in a pond being observed from above the water

(2)a fingerprint left at a crime scene being observed through a magnifying glass

(3)a motion picture on the screen being watched in a cinema

12.

Photograph of a girl reading small print with a magnifying glass

Cecilia uses a magnifying glass to read some small print. Which of the following diagrams shows how the image of the print is formed ?

Four ray diagrams A to D showing the image I of an object O formed by a lens

13.

Grid showing an object, a lens and an image on the principal axis; scale 5 cm

An object is placed near a lens and an image is formed as shown. Which of the following statements are correct ?

(1)The height of the image is half that of the object.

(2)The lens is a concave lens.

(3)The focal length of the lens is

20

cm.

14.

An object is placed in front of a concave lens. Which of the following statements about the properties of the image formed by the lens must be correct ?

(1)The image is diminished.

(2)The image is virtual.

(3)The image distance is smaller than the focal length of the lens.

15.

Object O in front of a concave lens with three incident rays; F and F' are the foci

An object $O$ is placed in front of a concave lens. $F$ and $F'$ are the foci of the lens. Which of the following diagrams shows the refracted rays of the three incident rays and the image $I$ correctly ?

16.

Photograph of a watch with a lens positioned over the date-display

The photograph shows a watch with a lens positioned over the date-display. Which of the following statements are correct ?

(1)The lens is a convex lens.

(2)The image of the date-display formed by the lens is virtual.

(3)The date-display and its image lie on the same side of the lens.

17.

Which of the following ray diagrams concerning the refraction of light ray by a converging lens is/are incorrect ? $F$ denotes the focus of the lens.

Three ray diagrams (1), (2), (3) for a convex lens

18.

Photograph of a student viewing a distant object through a hand-held convex lens

The photograph shows a student using a convex lens of focal length $20$ cm to view a distant object. Which of the following statements about the image formed is/are correct ?

(1)The image will be erect.

(2)The image will be diminished.

(3)The student must use a screen in order to see the image.

19.

Concave lens with foci F and F', incident ray AB and possible emergent rays P, Q, R and S

In the above figure, $F$ and $F'$ are the foci of the above lens and $AB$ is an incident ray. Which of the following paths best represents the emergent ray ?

20.

Questions 11 and 12 : An illuminated letter 'R' is placed in front of a lens as shown below and an image is formed on a translucent screen. The object distance is $30$ cm and the image distance is $20$ cm.

Illuminated letter R, lens and screen with object distance 30 cm and image distance 20 cm, and the observer's eye

Which of the following statements is/are correct ?

(1)The lens is a converging lens.

(2)The image is diminished.

(3)The shape of the image seen by the observer is 'R' reversed.