Question

A cocave mirror of focal lenth 10 cm is producing a 12 times virtual image of an object find the object distance from the mirror

Answer 1

Explanation:

gn.mirror - Concave mirror...

so,

f= (-10)cm ; m= 12;

to find - u=?

magnification- h'/h= -v/u....

12= -v/u

-12u = v

mirror formula - 1/v+1/u= 1/f

1/(-12u)+ 1/u = 1/(-10)

1/u= 1/(-10)+1/12u

1/u= -6+5/60u

1/u= -1/60u

u= (-60)cm

Answer 2

Explanation:

gn.mirror - Concave mirror...

so,

f= (-10)cm ; m= 12;

to find - u=?

magnification- h'/h= -v/u....

12= -v/u

-12u = v

mirror formula - 1/v+1/u= 1/f

1/(-12u)+ 1/u = 1/(-10)

1/u= 1/(-10)+1/12u

1/u= -6+5/60u

1/u= -1/60u

u= (-60)cm