Advertisements
Advertisements
Question
Explain the following term related to spherical lenses:- principal focus
Advertisements
Solution
Principal Focus:-
The convex lens converge the rays incident on it after refraction, to a point on the principal axis. This point is known as principal focus of the convex lens. The rays incident on concave lens appear to diverge from a point on the principal axis. This point is known as the principal focus of concave lens.
APPEARS IN
RELATED QUESTIONS
Explain the following term related to spherical lenses:- optical centre
A ray of light is incident on a plane mirror at an angle of 30°. What is the angle of reflection
A diverging lens is used in:
(a) a magnifying glass
(b) a car to see objects on rear side
(c) spectacles for the correction of short sight
(d) a simple camera
A concave lens produces an image 20 cm from the lens of an object placed 30 cm from the lens. The focal length of the lens is:
(a) 50 cm
(b) 40 cm
(c) 60 cm
(d) 30 cm
State the direction of incident ray which after reflection from a spherical mirror gets reflected along its own path. Give a reason.
Name the spherical mirror which (i) diverges (ii) converges the beam of light incident on it. Justify your answer by drawing a ray diagram in each case.
Write two more characteristics of the image.
Define the following term:
convex mirror
