5 cm high object is placed at a distance of 25 cm from a converging lens of focal length of 10 cm. Determine the position, size and type of the image.

5 cm high object is placed at a distance of 25 cm from a converging le

1.	5 cm high object is placed at a distance of 25 cm from a converging lens of focal length of 10 cm. Determine the position, size and type of the image.
Answer» Solution :Given: Focal length (f) = 10 cm, object distance (u) = - 25 cm, height of the object `(h_(1)) = 5 cm` To find: Image distance (v), height of the image `(h_(2))` Formulae: i. `(1)/(f)=(1)/(v)-(1)/(u)` ii. `(h_(2))/(h_(1))=(v)/(u)` CALCULATION: From formula (i), `(1)/(10)=(1)/(v)-(1)/(-25)` `therefore" "(1)/(v)=(1)/(10)-(1)/(25)=(5-2)/(50)` `therefore" "(1)/(v)=(3)/(50)` `therefore" "v=16.7 cm` As the image distance is positive, the image formed is REAL. From formula (ii), `(h_(2))/(5)=(16.7)/(-25)` `therefore" "h_(2)=(16.7)/(25)xx5=-(16.7)/(5)` `therefore" "h_(2)=-3.3 cm` The NEGATIVE SIGN indicates that the image formed is inverted.