Question

an object is placed at 10cm in front of a concave mirror of focal length 15cm . At what distance from the mirror obtain a sharp image​

Answer 1

Explanation:

Solution :-. Given u = -10cm , v= ? , f = -15cm

Applying mirror's formula,1/v +1/u = 1/f

1/v + 1/-10 = 1/-15

1/v = -1/15 + 1/10

=(-2+3)/30

= 1/30

V = 30 cm.

Hence, we get enlarged image, virtual in nature having magnification 3.

Answer 2

Using mirror formula, f1=v1+u1

−151=v1+−251

v1=75−5+3

v=−37.5cm

Hence, position of image at 37.5cm infront of the mirror.

Magnification(M)=hohi=u−v=−2537.5=−1.5

hi=−1.5×hO

hi=−1.5×7=−10.5cm

Hence,size of image is −10.5cm.

Nature of image is real,inverted and magnified.