Question

focal length of the comcave lens is 20cm an object is placed 15cm distance from the pole find the image distamce height of the image and mention the characteristics of the image​

Answer 1

Answer:

f= -20cm

u= -15cm

v= ?

1/v - 1/u = 1/f

therefore, 1/v = 1/f + 1/u

1/v = 1/-20 + 1/-15

1/v = 1/-20 - 1/15

1/v = (-3-4)/60 (by taking LCM)

1/v = -7/60

v = -60/7

v = -8.57(approx)

the image formed by lense is

real and inverted

thanks for your....

Answer 2

given, focal length of concave mirror, f = -20 cm

distance of object from the mirror, u = -10 cm

use formula, 1/v + 1/u = 1/f

or, 1/v = 1/f - 1/u

or, 1/v = 1/-20 - 1/-10

or, 1/v = -1/20 + 1/10 = 1/20

or, v = +20cm

hence, image position is 20cm right side from the pole of concave mirror