Question

# A beam of light converges at a point P. Now a lens is placed in the path of the convergent beam 12 cm from P. At what point does the beam converge if the lens is (a) a convex lens of focal length 20 cm, and (b) a concave lens of focal length 16 cm?

Solution
Verified by Toppr

#### (a). According to the given case, object is virtual, u=+12 cmThe focal length of the convex lens is f=+20 cm.Using lens equation, 1v−1u=1f1v−112=120v=7.5 cm(b). Now the focal length of the concave lens, f=−16 cm1v−1u=1f1v−112=1−16v=48 cm

8
Similar Questions
Q1

Figure given below shows a beam of light converging at point P. When a convex lens of focal length 16 cm is introduced in the path of the beam at a place O shown by dotted line, the beam converges at a distance x from the lens. The value x will be equal to View Solution
Q2

A diverging lens with magnitude of focal length 25cm is placed at a distance of 15cm from a converging lens of magnitude of focal length 20cm. A beam of parallel light falls on the diverging lens. The final image formed is

View Solution
Q3

A beam of light converges to a point P. A concave lens of focal length 16 cm is placed in the path of the convergent beam 12 cm from P. How far from the lens does the beam converge? View Solution
Q4

A beam of light converges to a point P. A concave lens of focal length 16 cm is placed in the path of the convergent beam 12 cm from P. How far from the lens does the beam converge? View Solution
Q5

A converging beam of light falls on one surface of the biconcave lens whose other surface is silvered. After reflection from the silvered lens, the beam converges to a point 24 cm in front of the lens. The focal length of the lens is 30 cm and the silvered surface has a radius of curvature equal to 50 cm. Where will the beam of light converge if the lens is removed from its path?

View Solution
Solve
Guides