Question

mirror formula class 10th

Answer 1

A formula which gives the relationship between image distance (v),object distance(u), and focal length(f) of a spherical mirror is known as the mirror formula .

Mirror formula can be written as:

$\frac{1}{f} = \frac{1}{v} + \frac{1}{u}$
where,

v= distance of image from mirror

u= distance of object from mirror

f= focal length of the mirror


The distance of an object from the pole of mirror is known as object distance. object distance is denoted by the letter u.

The distance of image from the pole of a mirror is known as image distance. image distance is denoted by the letter v.

The distance of focus from the pole of a mirror is known as focal length. focal length is denoted by the letter f.

Answer 2

Hey mate ^_^

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Answer:
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In Triangles BAC and A’B’C'
AB/A’B’ = CB/CB’  - - - - - (i)

Now, 

Triangle ABP and A’B’P’ are similar,
AB/A’B’ = PB/PB’ - - - - - (ii)

From (i) & (ii)

CB/CB’= PB/PB’  - - - - - - (iii)

Measuring all distances from P,

We have,

CB= PB-PC CB’= PC-PB’

Therefore from (iii),

(PB-PC)/(PC-PB’) = PB/PB’  - - - - - (iv)

Using new cartesian sign convections,

PB= -u (distance of object)

PC= -R PB’ = -v (distance of image)

We get from (iv),
     
uR + vR = 2uv  

Dividing both sides by uvR,

We get,

1/v + 1/u = 2/R    

R=2f

Therefore,

1/v + 1/u = 2/R = 2/2f = 1/f

This is the required formula.

#Be Brainly❤️