Question

1. An object is placed infront of a concave mirror of
radius of curvature 40 cm at a distance of 10 cm. Find
the position, nature and magnification of the image.

Answer 1

Answer:

Given, u=−10cm,R=15cm,∴f=

2

R

=−

2

15

cm

From mirror formulae,

v

1

+

u

1

=

f

1

⇒

v

1

=

f

1

−

u

1

⇒

v

1

=

10

1

−

15

2

⇒v=−30

Nature of image is real and inverted.

Answer 2

Answer:

R

Explanation:

in concave mirror, u, R, f are on left side. so all of them will be having negative sign with them.

R= 40 cm

we know that, R= 2f

so 40= 2f

f =20 cm.

u = 10cm

by applying mirror formula and sign of conventions

1/f = 1/v +1/u

1/-20 =1/v +1/-10

1/v= 1/-20 - 1/-10

1/v =1/20

that ia the image formed is erect, virtual and on the other side of the mirror.

hope you understand. keep studying, keep growing!