Question

An object is placed at the following distances from a convex lens of focal length 10 cm. 

(a) 8 cm. 

(b) 15 cm. 

(c) 20 cm. 

(d) 25 cm. 

Which position of the object will produce…….

(i) a diminished, real and inverted image? 

(ii) a magnified, real and inverted image? 

(iii) a magnified, virtual and erect image? 

(iv) an image of same size as the object? Justify your answer in each case.

Answer 1

i) d (or) 25 cm 

Reason : Object placed between centre of curvature and focal point.

ii) b (or) 15 cm 

Reason : Object placed beyond centre of curvature

iii) a (or) 8cm 

Reason : Object placed between focal point and optic centre.

iv) c (or) 20 cm 

Reason :Object placed at centre of curvature.