Question

a concave mirror of focal length 10cm produces a real image on its axis 20cm away from the mirror. find the position of an object ​

Answer 1

Answer:

THE POSITION OF THE OBJECT IS -20cm.

Explanation:

Given,

In case of concave mirror,,

f (focal length) = -10cm (in front of the mirror)

v (image distance) = -20cm (in front of the mirror)

BY THE MIRROR FORMULA,,

1/u + 1/u = 1/f

; 1/u + (1/-20) = -1/10

; 1/u = 1/20 - 1/10

; 1/u = 1-2/20

; 1/u = -1/20.

RECIPROCAL THE FRACTION,,

; u = -20cm

HOPE IT WILL BE HELPFUL

Answer 2

Answer:

The position of the object is -20 cm .

Explanation:

Given information :

The mirror in question is a concave mirror.

• We can say that the reflective surface of a concave mirror is curled inward and away from the light source.
• Furthermore, light is reflected inward to a single focal point via concave mirrors.
• Concave mirrors, in contrast to convex mirrors, produce a variety of images depending on the object's proximity to the mirror.

Focal length (f) = -10cm

Focal length in this case will be in front of the mirror

Image distance (v) = -20

Image distance in this case will be in front of the mirror

Solution :

We know that by the formula :

1/u +1/v = 1/f

• This above equation is known as lens formula and When the lens is thin and medium on both sides are the same, the lens formula is valid.

1/u + (1/-20) = -1/10

: 1/u = 1/20 - 1/10

: 1/u = 1-2/20

: 1/u = -1/20.

When we reciprocal the fraction both at LHS and RHS we get,

:u=-20cm

Therefore according to our above calculation we can say that the position of the image is -20cm.

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