Question

Find the distance of the image when an object is placed on the principal axis at a distance of 10cm in front of a conacve mirror of radius 8cm

Answer 1

Answer:

Mirror formula is 1/f = 1/v + 1/u

since u =10cm (-) object distance is taken as negative

and you are given radius of curvature which is - 8 since the mirror is a concave mirror the radius of curvature will be negative

and focal length= radius /2

therefore f= -4 cm

and now use the mirror formula

as mentioned above

1/-4 = 1/v +1/-10

therefore v= 40/30 = 4/3 = 1.33

Answer 2

Answer:

Radius of Curvature (R): 8 cm

Focal Length (f) = R/2 = 8/2 = 4 cm

Object distance (u) = -10 cm

Image Distance (v) = ?

We know that,

Mirror Formula:

= 1/f = 1/v + 1/u

= -1/4 = 1/v - 1/10

= -1/4 + 1/10 = 1/v

= 1/v = $\frac{-5+2}{20}$

= 1/v = -3/20

v = -20/3 cm = $6\frac{2}{3}$cm

∴ Real Images are Inverted.