Chapter 23 Sample Multiple Choice Problems   

 

1.       If you stands 2.0 m in front of a plane mirror, how far away would you see the image of yourself?

a.       1.0 m              

b.      2.0 m    

c.   4.0 m

          d.   8.0 m

 

2.       A plane mirror forms an image that is

          a.   real and upright.

          b.   virtual and upright.

          c.   real and upside down.

d.      virtual and upside down.

 

 3.     A concave mirror with a radius of 20 cm creates a real image 30 cm from the mirror.  What is the

    object distance?

          a.   20 cm

          b.   15 cm

          c.   7.5 cm

          d.   5.0 cm

 

4.      A person's face is 30 cm in front of a concave shaving mirror.  If the image is an erect image 1.5

   times as large as the object, what is the mirror's focal length?

          a.   20 cm

          b.   50 cm

          c.   70 cm

          d.   90 cm

 

5.      An object is placed 15 cm from a concave mirror of focal length 20 cm. The object is 4.0 cm tall. 

   How tall is the image?

          a.   1.0 cm

          b.   2.0 cm

          c.   8.0 cm

d.      16 cm

 

6.      An object is placed at a concave mirror's center of curvature.  The image produced by the mirror

    is located

          a.   out beyond the center of curvature.

          b.   at the center of curvature.

          c.   between the center of curvature and the focal point.

          d.   at the focal point.

 

7.      An object is situated between a concave mirror's surface and its focal point.  The image formed

    in this case is

          a.   real and inverted.

          b.   real and erect.

          c.   virtual and erect.

d.      virtual and inverted.

 

8.      An object is 47.5 cm tall.  The image is 38.6 cm tall, and 14.8 cm from the mirror.  How far is the  

         object from the mirror?

          a.   124 cm

          b.   47.6 cm

          c.   18.2 cm

          d.   12.0 cm

 

9.      An object is 5.7 cm from a concave mirror.  The image is 4.7 cm tall, and 10 cm from the mirror. 

         How tall is the object?

          a.   12 cm

          b.   11 cm

          c.   8.2 cm

          d.   2.7 cm

 

10.    An object is 14 cm in front of a convex mirror.  The image is 5.8 cm behind the mirror.  What is

   the focal length of the mirror?

          a.   -4.1 cm

          b.   -8.2 cm

          c.   -9.9 cm

          d.   -20 cm

 

11.    A convex spherical mirror has a focal length of -20 cm.  An object is placed 10 cm in front of the

   mirror on the mirror's axis.  Where is the image located?

          a.   20 cm behind the mirror.

          b.   20 cm in front of the mirror.

          c.   6.7 cm behind the mirror.

          d.   6.7 cm in front of the mirror.

 

12.     Convex spherical mirrors produce images which

          a.   are always smaller than the actual object.

          b.   are always larger than the actual object.

          c.   are always the same size as the actual object.

c.       could be larger than, smaller than, or the same size as the actual object, depending on the

      placement of the object.

 

13.    A ray of light, which is traveling in air, is incident on a glass plate at a 45 degree angle.  The angle

   of refraction in the glass

          a.   is less than 45 degrees.

          b.   is greater than 45 degrees.

          c.   is equal to 45 degrees.

          d.   could be any of the above; it all depends on the index of refraction of glass.

 

14.    The critical angle for a beam of light passing from water into air is 48.8 degrees.  This means that

   all light rays with an angle of incidence greater than this angle will be

          a.   absorbed.

          b.   totally reflected.

          c.   partially reflected and partially transmitted.

          d.   totally transmitted.

 

15.    A convex lens has focal length f.  An object is placed at 2f on the axis.  The image formed is

          located

          a.   at 2f.

          b.   between f and 2f.

          c.   at f.

          d.   between the lens and f.

 

16.    A convex lens has a focal length f.  An object is placed between f and 2f on the axis.  The image

   formed is located

          a.   at 2f.

b.      between f and 2f.

c.       at f

d.      between the lens and f.

 

17.     A object is placed between a convex lens and its focal point.  The image formed is

          a.   virtual and erect.

          b.   virtual and inverted.

          c.   real and erect.

          d.   real and inverted.

 

18.    An object is placed 40 cm in front of a 20 cm focal length converging lens.  How far is the image

   of this object from the lens?

          a.   40 cm

          b.   20 cm

          c.   13 cm

          d.   None of the above.

 

19.     An object is 12 cm in front of a converging lens with focal length 4 cm.  Where is the image?

          a.   8.0 cm behind the lens

          b.   6.0 cm in front of the lens

          c.   6.0 cm behind the lens

          d.   4.0 cm in front of the lens

 

20.    An object is placed at a distance of 40 cm from a thin lens.  If a virtual images forms at a distance

   of 50 cm from the lens, on the same side as the object, what is the focal length of the lens?

          a.   45 cm

          b.   75 cm

          c.   90 cm

          d.   200 cm

 

21.    An object is placed at a distance of 30 cm from a thin convex lens.  The lens has a focal length of

   10 cm.  What are the values, respectively, of the image distance and lateral magnification?

          a.   15 cm, 2.0

          b.   25 cm, 1.0

          c.   60 cm, -0.50

          d.   15 cm, -0.50

 

22.    A 14 mm tall object is 4.0 mm from a converging lens.  If the image is 4.0 mm tall, how far is it

   from the lens?

          a.   14 mm

          b.   8.7 mm

          c.   1.4 mm

          d.   1.1 mm

 

23.     An object is 4.1 cm tall, and 10.3 cm from a converging lens.  The image is virtual and 6.2 cm tall. 

         What is the focal length of the lens?

          a.   6.8 cm

          b.   10 cm

          c.   16 cm

          d.   30 cm

 

24.    An object is 10.4 cm tall, and 4.8 cm in front of a diverging lens.  The image is 4.0 cm from the lens. 

   How tall is the image?

          a.   13 cm

          b.   8.7 cm

          c.   5.4 cm

e.       1.8 cm

 

25.    How far from a lens of focal length 50 mm must the object be placed if it is to form a virtual image

          magnified in size by a factor of three?

          a.   33 mm

          b.   42 mm

          c.   48 mm

d.      54 mm

 

 

Answers:

1.       c

2.       b

3.       b

4.       d

5.       d

6.       b

7.       c

8.       c

9.       d

10.     c

11.     c

12.     a

13.     a

14.     b

15.     a

16.     d

17.     a

18.     a

19.     c

20.     d

21.     d

22.     d

23.     d

24.     b

25.    a