Question

4. A 5 cm tall light bulb is placed at a distance of 40 cm from a convex mirror having a focal length of -15 cm.
Determine the image distance and the image size.
5. A 10 cm tall light bulb placed at a distance of 50 cm form a concave mirror having a focal length of 20 cm.
Determine the image distance and the image size.

Answer 1

Answer:

The correct option is D

5

6

c

m

Using mirror formula,

1

u

+

1

v

 =

1

f

1

−

50

+

1

v

=

1

10

(u is negative and f is positive for a convex mirror)

Solving, we get:

v

=

50

6

c

m

Using the formula for magnification,

m

=

−

v

u

=

h

′

h

−

50

/

6

−

50

=

h

′

5

h

′

=

5

6

c

m

Explanation: