Question

an object is placed at a distance 20cm from a concave mirror of focal length 12cm where will the image form​

Answer 1

Answer:

-30 cm

Explanation:

According to the given question,

u = object distance = -20 cm

f = focal length = -12 cm

v = image distance = ?

And we are asked to find image distance.

We know for concave mirror,

• 1/f = 1/u + 1/v

Putting the values we get,

• 1/-12 = 1/-20 + 1/v

• 1/v = 1/20 - 1/12

• v = 20×12/(-8)

• v = - 5×12/2

• v = -5×6

• v = -30 cm

Thus image will be formed at the distance of 30 cm from the mirror.

Here negative sign indicates that image is opposite to the direction of rays which are coming from the object towards lens.

Answer 2

Answer:

Explanation:

See the answer given below