Question

an object height 5 cm is placed perpendicular of the principal axis of concave lens of focal length 10 cm.use lens formula to determine position size and nature of image.if distance of object for the lens is 20 cm.​

Answer 1

Answer:Given: Object height, h =+5 cm

Focal length, f = -10 cm

Object distance, u = -20 cm

Applying the lens formula:

 1/f= 1/v-/u

Putting values

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

1/v=3/-20

v= -20/3

V=  -6.67 cm

Now height of image can be calculated as follows:

h2/h1=v/u

h2=5/ 3

h2=1.67 cm

therefore, the image formed will be virtual, erect and diminished in size.