Question

A conve mirror products 3 times enlarged image of an it object placed 10cm in front of it. calculate radius of curvature
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Answer 1

Given :

→ Lateral magnification = -3

→ Distance of object = -10cm

→ Type of mirror : concave

To Find :

→ Radius of curvature of mirror.

Formula :

↗ Mirror formula :

☢ 1/u + 1/v = 1/f = 2/R

↗ Lateral magnification :

☢ m = - v / u

• v denotes distance of image
• u denotes distance of object
• f denotes focal length
• R denotes radius of curvature
• m denotes magnification

Calculation :

☞ m = - v / u

☞ (-3) = - v / (-10)

☞ v = -30cm

→ 1/u + 1/v = 2/R

→ 1/(-10) + 1/(-30) = 2/R

→ (-3 - 1)/30 = 2/R

→ -4/30 = 2/R

→ -2/30 = 1/R

→ R = -15cm

Answer 2

Given ,

• Lateral magnification = -3

• Distance of object = -10cm

To Find:-

Radius of curvature

Formula used:-

• 1/u + 1/v = 1/f =2/R
• m= - v/u

m= magnification

v=image

u=distance of object

f= focal length

R= radius of curvature.

Calculations:-

m = - v / u

(-3) = - v / (-10)

v = -30cm

1/u + 1/v = 2/R

1/(-10) + 1/(-30) = 2/R

(-3 - 1)/30 = 2/R

-4/30 = 2/R

-2/30 = 1/R

R = -15cm

The radius of curvature is (-15cm)