Light reflection and refraction Worksheet-5
A. Towards normal
B. Away from normal
C. Neither towards nor away from normal
D. Cannot say
A. Rarer to denser medium
B. Denser to rarer medium
C. One medium to other medium of same optical density
D. Cannot say
A. 2/3 B. 1 C. Zero D. (3/2)2
A. 4 m B. 3 m C. 7 m D. 1 m
A. Object distance B. Image distance
C. Nature of material D. None of these
A. –2 D B. –(1/2)D C. 2D D. (1/2)D
A. 15 cm B. 30 cm C. 60 cm D. 10 cm
A. < 20 cm
B. > 20 cm
C. < 20 cm and between 20 cm and 40 cm
D. Cannot say
A. Water B. Glass C. Plastic D. Clay
A. between the focus and centre of curvature,
B. at the centre of curvature,
C. beyond the centre of curvature,
D. Between the pole of the mirror and focus.
A. At the principal focus of the lens,
B. At twice the focal length,
C. At infinity,
D. Between the optical centre of the lens and its principal focus.
A. Both are concave.
B. Both are convex
C. The mirror is concave, but the lens is convex.
D. The mirror is convex, but the lens is concave.
A. plane B. concave
C. convex D. either plane or convex.
A. Convex lens of focal length 50 cm
B. A concave lens of focal length 50 cm
C. A convex lens of focal length 5 cm
D. A concave lens of focal length 5 cm.
Answer Key:
Clay cannot be used to make a lens as it is not transparent.
For virtual, erect and larger image, the object must lie between the pole of the mirror and its focus.
The object is to be placed at twice the focal length of the lens.
As per New Cartesian Sign Conventions, the focal length of a concave mirror and focal length of a concave lens, both are negative. Therefore, both are concave.
The image is erect in a plane mirror and also in a convex mirror, for all positions of the object.
For reading small letters in a dictionary, we should use a convex lens of smaller focal length.