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Free download in PDF Class 12 Physics Chapter 9 Ray Optics and Optical Instruments Multiple Choice Questions and Answers for Board, JEE, NEET, AIIMS, JIPMER, IIT-JEE, AIEE and other competitive exams. MCQ Questions for Class 12 Physics with Answers were prepared based on the latest exam pattern. These short solved questions or quizzes are provided by Gkseries. These will help the students for preparation of their examination./p>
(1)
An astronomical refractive telescope has an objective of focal length 20 m and an eyepiece of focal length 2 cm. Then
[A]
the magnification is 1000
[B]
the length of the telescope tube is 20.02 m
[C]
the image formed of inverted
[D]
all of these
(2)
Two beams of red and violet color are made to pass separately through a prism (angle of the prism is 60°). In the position of minimum deviation, the angle of refraction will be
[A]
30° for both the colors
[B]
greater for the violet color
[C]
greater for the red color
[D]
equal but not 30° for both the colors
Answer: 30° for both the colors
(3)
Which of the following forms a virtual and erect image for all positions of the object?
[A]
Concave lens
[B]
Concave mirror
[C]
Convex mirror
[D]
Both (a) and (c)
(4)
Mirage is a phenomenon due to
[A]
refraction of light
[B]
reflection of light
[C]
total internal reflection of light
[D]
diffraction of light.
Answer: total internal reflection of light
(5)
Two lenses of focal lengths 20 cm and – 40 cm are held in contact. The image of an object at infinity will be formed by the combination at
[A]
10 cm
[B]
20 cm
[C]
40 cm
[D]
infinity
(6)
Which of the following colours of white light deviated most when passes through a prism?
[A]
Red light
[B]
Violet light
[C]
Yellow light
[D]
Both (a) and (b)
(7)
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
[A]
become zero
[B]
become infinite
[C]
become small, but non-zero
[D]
remain unchanged
(8)
An under-water swimmer cannot see very clearly even in absolutely clear water because of
[A]
absorption of light in water
[B]
scattering of light in water
[C]
reduction of speed of light in water
[D]
change in the focal length of eye lens
Answer: change in the focal length of eye lens
(9)
For a total internal reflection, which of the following is correct?
[A]
Light travels from rarer to denser medium.
[B]
Light travels from denser to rarer medium.
[C]
Light travels in air only.
[D]
Light travels in water only.
Answer: Light travels from denser to rarer medium.
(10)
A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 ’em in such a way that its end closer to the pole is 20 cm away from the mirror. The length of the image is
[A]
10 cm
[B]
15 cm
[C]
2.5 cm
[D]
5 cm
(11)
The branch of optics dealing with the formation of images using the concept of straight line propagation of light is called:
[A]
geometrical optics
[B]
physical optics
[C]
corpuscular optics
[D]
quantum optics
(12)
The air bubble inside water shine due to:
[A]
Reflection
[B]
Refraction
[C]
T.l.R.
[D]
None of these
(13)
When light travels from one medium to another, which of the following does not change?
[A]
frequency
[B]
refractive index
[C]
velocity
[D]
wavelength
(14)
A thin glass (RI = 3/2) lens has optical power of – 5D in air. Its optical power in a liquid medium with RI = 1.6 will be:
[A]
-2.5 D
[B]
25 D
[C]
-ID
[D]
0.625 D
(15)
The refractive indices (R.I.) of glass and water with respect to air are 3/2 and 4/3 respectively. The R.I. of glass w.r. to w ater is:
[A]
8/9
[B]
9/8
[C]
7/6
[D]
2
(16)
A convergent lens will become less convergent in :
[A]
oil
[B]
water
[C]
both of (a) and (b)
[D]
none of these
(17)
If a mirror is approaching you at a speed of 10 ms^1, the speed with which your image approach you is:
[A]
10 ms-1
[B]
5 ms-1
[C]
20 ms-1
[D]
15 ms-1
(18)
Which of the following cannot be polarised?
[A]
radiowaves
[B]
transverse waves
[C]
sound waves
[D]
X-rays
(19)
Two lens of power -15 D and +5 D are placed in contact co-axially. The focal length of equivalent lens is:
[A]
-10 cm
[B]
-20 cm
[C]
+10 cm
[D]
None
(20)
When a ray of light (white) enters a lens, undergoes a change is:
[A]
wavelength
[B]
velocity
[C]
frequency
[D]
both velocity and wavelength
Answer: both velocity and wavelength
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