物理透鏡 DSE、CE 選擇題

1.

An object is placed in front of a concave lens. Which of the following descriptions about the image formed by the lens is incorrect ?

2.

Object O and its upright image I on the principal axis, with points X and Y

The figure above shows an object $O$ and its image $I$ formed by a lens. Which of the following about the lens used and its position is correct ?

	Type of lens	Position of lens
	concave	$X$
	concave	$Y$
	convex	$X$
	convex	$Y$

3.

Two parallel rays X and Y meeting at P after passing through lens L; ray Z parallel to the principal axis; points Q, R, S on the axis

Two parallel rays $X$ and $Y$ meet at $P$ after passing through lens $L$ as shown. Another ray $Z$ parallel to the principal axis is directed to lens $L$ . Which point in the figure will ray $Z$ pass through ?

4.

A student puts a lens at a certain distance above a paper with the word "TEST" written on it as shown in the figure. What is the lens ? If the student moves the lens further away from the paper, what will be the change in the size of the image ?

The word TEST magnified by a circular lens held over a ruled paper

	lens	change in size of the image
	convex	increases
	convex	decreases
	concave	increases
	concave	decreases

5.

Light bulb X and convex lens L with the light converging beyond the lens

In the above figure, $X$ is a light bulb and $L$ is a convex lens. Which of the following ways can be used to produce a parallel beam of light rays ?

(1)Moving

L

closer to

X

.

(2)Replacing

L

with another convex lens of longer focal length

(3)Replacing

L

with another concave lens of shorter focal length

6.

Light bulb O, lens L and screen S on a line

A light bulb $O$ is placed in front of a lens $L$ as shown above. A sharp and diminished image is formed on the screen $S$ . With the position of $L$ fixed, which of the following methods can form a sharp and magnified image on the screen ?

7.

Which of the following ray diagrams concerning the refraction of two light rays by a converging lens is/are possible ?

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

8.

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

$F$ and $F'$ are the foci of the above lens and $AB$ is an incident ray. Which light ray best represents the emergent ray ?

9.

The figure shows a web cam. A web cam typically includes a lens and an image sensor. The function of the image sensor is similar to that of a film in a conventional camera. The image is formed on the sensor and is then digitised. Which of the following statements is/are correct ?

(1)The lens is a convex lens.

(2)The lens is a concave lens.

(3)Image formed on the image sensor is real.

10.

Grid showing an illuminated object, a convex lens and a screen; scale 5 cm

As shown above, an illuminated object is placed at a distance $20$ cm in front of a convex lens and a sharp image is formed on a screen at a distance of $16$ cm from the lens. The focal length of the convex lens is