HARD
JEE Main
IMPORTANT
Earn 100

Consider the situation described in the previous problem. Where should a point source be placed on the principal axis, so that the two images form at the same place?

Important Questions on Geometrical Optics

MEDIUM
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 18 - Geometrical Optics>EXERCISES>Q 66
A converging lens of focal length 15 cm and a converging mirror of focal length 10 cm are placed 50 cm apart. If a pin of length 2.0 cm is placed 30 cm from the lens farther away from the mirror, where will the final image form and what will be the size of the final image?
HARD
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 18 - Geometrical Optics>EXERCISES>Q 67
A point object is placed on the principal axis of a convex lens (f=15 cm) at a distance of 30 cm from it. A glass plate (μ=1.50) of thickness 1 cm is placed on the other side of the lens perpendicular to the axis. Locate the image of the point object.
HARD
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 18 - Geometrical Optics>EXERCISES>Q 68
A convex lens of focal length 20 cm and a concave lens of focal length 10 cm are placed 10 cm apart with their principal axes coinciding. A beam of light travelling parallel to the principal axis and having a beam of diameter 5.0 mm, is incident on the combination. Show that the emergent beam is parallel to the incident one. Find the beam diameter of the emergent beam.
HARD
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 18 - Geometrical Optics>EXERCISES>Q 69
A diverging lens of focal length 20 cm and a converging lens of focal length 30 cm are placed 15 cm apart with their principal axes coinciding. Where should an object be placed on the principal axis so that its image is formed at infinity?
HARD
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 18 - Geometrical Optics>EXERCISES>Q 70
A 5 mm high pin is placed at a distance of 15 cm from a convex lens of focal length 10 cm. A second lens of focal length 5 cm is placed 40 cm from the first lens and 55 cm from the pin. Find
(a) the position of the final image,
(b) its nature and
(c) its size.
HARD
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 18 - Geometrical Optics>EXERCISES>Q 71
A point object is placed at a distance of 15 cm from a convex lens. The image is formed on the other side at a distance of 30 cm from the lens. When a concave lens is placed in contact with the convex lens, the image shifts away further by 30 cm. Calculate the focal lengths of the two lenses.
HARD
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 18 - Geometrical Optics>EXERCISES>Q 72

Two convex lenses, each of focal length 10 cm, are placed at a separation of 15 cm with their principal axes coinciding.

(a) Show that a light beam coming parallel to the principal axis diverges as it comes out of the lens system.

(b) Find the location of the virtual image formed by the lens system of an object placed far away.

(c) Find the focal length of the equivalent lens. (Note that the sign of the focal length is positive, although the lens system actually diverges a parallel beam incident on it).

HARD
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 18 - Geometrical Optics>EXERCISES>Q 73
A ball is kept at a height h above the surface of a heavy transparent sphere made of a material of refractive index μ. The radius of the sphere is R. At t=0, the ball is dropped to fall normally on the sphere. Find the speed of the image formed as a function of time for t<2hg. Consider only the image by a single refraction.