A lens forms a real image of an object placed at a distance of 60 cm from it. If

A lens forms a real image of an object placed at a distance of 60 cm from it. If the image distance is 15 cm, what is the focal length of the lens?

A lens forms a real image of an object placed at a distance of 60 cm from it. If the image distance is 15 cm, what is the focal length of the lens?

Step 1: Identify the given values. The object distance (u) is -60 cm (negative because it is on the same side as the object) and the image distance (v) is 15 cm.
Step 2: Write down the lens formula: 1/f = 1/v - 1/u.
Step 3: Substitute the values into the lens formula: 1/f = 1/15 - 1/(-60).
Step 4: Calculate 1/15, which is 0.0667, and 1/(-60), which is -0.0167.
Step 5: Now, calculate 1/f: 1/f = 0.0667 + 0.0167 = 0.0834.
Step 6: To find the focal length (f), take the reciprocal of 0.0834: f = 1/0.0834.
Step 7: Calculate f, which gives approximately 12 cm.

Lens Formula – The lens formula relates the focal length (f), image distance (v), and object distance (u) of a lens, expressed as 1/f = 1/v - 1/u.
Real Image Formation – A real image is formed on the opposite side of the lens from the object and can be projected onto a screen.