# An object 2cm in size is placed 20cm in front of a concave mirror of focal lenght 10cm. Find the distance from the mirror at which a screen should be placed in order to obtain a clear image. What will be the size and nature of the image formed? Answer fast plzz fa tomorrow

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Here, f= -10cm , h1=+2cm , u=-20cm , v=?
Using mirror formula, we have
1/f= 1/u + 1/v ,1/v = 1/f -1/u
1/v =-1/10 +1/20 = -1/20
v= -20cm
Since v is -ve, thus position of image is 20cm in front of the mirror.
And since it is formed in front of the mirror , it must be real and inverted.
Using the expression for linear magmification,
m=h2/h1 =-v/u
Here, h1=+2cm , v=-20cm , u=-20cm , we have
h2/2 = (-20/-20)=1
Thus h2 = 2cm
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The screen should be placed at the centre of curvature of the mirror , that is where object is placed to get a clear image of the object.

In concave mirror , the image formed is always real and inverted except for one case , that is , when the object is too near , between pole and focus of the mirror which is not the case here.

Size of the image = ((- ( distance of the image from pole of the mirror ) * size of the object )) / distance of the object from the pole of the mirror
= - 20 * 2 / 20
= - 2 cm
Therefore , the image formed is of size 2 cm on the same side as the object.
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