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Worksheetsray optics
Total questions: 15
Worksheet time: 8mins
Critical angle and refractive index are:
Directly related
Equal
Inversely related
None of these
A real image is formed by a a convex lens, then it is put in contact with a concave lens and again a real image is formed. This image is : ______________
shift towards the lens system
shift away from the lens system
remain in its original position
shift to infinity
Tom’ lenses of focal lengths ± 15 cm and ± 150 cm are available for making a telescope. To produce the largest magnification, the focal length of the eyepiece should be
+ 15 cm
+ 150 cm
– 150 cm
– 15 cm
A convex lens of refractive index 3/2 has a power of 2.5 D in air. If it is placed in a liquid of refractive index 2 then the new power of the lens is
– 1.25 D
– 1.5 D
1.25 D
1.5 D
A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length will
become zero
become infinite
become small, but non-zero
remain unchanged
You are given four sources of light each one providing a light of a single colour – red, blue, green and yellow. Suppose the angle of refraction for a beam of yellow light corresponding to a particular angle of incidence at the interface of two media is 90°. Which of the following statements is correct if the source of yellow light is replaced with that of other lights without changing the angle of incidence?
The beam of red light would undergo total internal reflection.
The beam of red light would bend towards normal while it gets refracted through the second medium.
The beam of blue light would undergo total internal reflection.
The beam of green light would bend away from the normal as it gets refracted through the second medium
If the critical angle for total internal reflection from a medium to vacuum is 30o, the velocity of light in the medium is
3 X 108 m/s
1.5 X 108 m/s
0.5 X 108 m/s
0.2 X 108 m/s
The magnifying power of an astronomical telescope in normal adjustment is 100. The distance between the objective and the eyepiece is 101 cm. The focal length of the objectives and eyepiece is
10 cm and 1 cm respectively
100 cm and 1 cm respectively
1 cm and 100 cm respectively
1 cm and 10 cm respectively
Which of the following statement is correct?
Refractive index of core and cladding are equal.
Refractive index of core is more then that of cladding.
Refractive index of core is less then that of cladding.
Refractive index of core is less or equal to that of cladding.
Which color has the shortest wavelength?
Red
Orange
Green
Violet
A glass lens is immersed in water. What will be the effect on the focal length of lens?
increases
decreases
remains constant
answer does not depend upon the medium
The line A & B in the ray diagram of figure represent a _______________ lens.
converging
Diverging
flint glass n=1.70
barium glass n=1.60
crown glass n=1.523
water n=1.33
diamond n=2.45
Green light traveling through air enters water (n=1.33) at a 20o angle, with respect to the normal. Which does not change upon entering the water? Select all that apply.
frequency
wavelength
speed
velocity
angle (measured from the normal)
