Question

✴️✴️ AHOLA FRIENDS✴️✴️

➡️➡️Find the position of an object which when placed in front of a focal length 20 cm produces a virtual image,which is twice the size of the object.??⬅️⬅️

#Be Brainly....

Answer 1

given:

focal length 

f= -20cm

and magnification

m = +2 = -v/u

or

v= -2u_______(1)

now, the mirror relation is

1/f = 1/v + 1/u

or

-1/20 = u + v/uv

            = u-2u /-2u2   [substituting value of v from eq. (1)]

thus, image distance will be

u= -10cm

Answer 2

given:

focal length 

f= -20cm

and magnification

m = +2 = -v/u

or

v= -2u_______(1)

now, the mirror relation is

1/f = 1/v + 1/u

or

-1/20 = u + v/uv

            = u-2u /-2u2   [substituting value of v from eq. (1)]

thus, image distance will be

u= -10cm