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Free download in PDF Lenses Multiple Choice Questions and Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams like IIT-JEE, JIPMER, NEET, AIIMS etc. These short solved questions or quizzes are provided by Gkseries.
(1)
In the case of a concave mirror, the image of an object is
[A]
Real, erect and diminished when the object lies beyond the centre of curvature
[B]
Real, inverted and of the same size as the object when it lies between the centre of curvature and focus
[C]
Real, inverted and diminished when the object lies beyond the centre of curvature
[D]
Not real, large and unproportional
Answer: Real, inverted and diminished when the object lies beyond the centre of curvature
(2)
To increase the magnifying power of a telescope, the focal length of
[A]
Objective lens should be increased
[B]
Objective lens should be decreased
[C]
Eye-piece lens should be increased
[D]
Eye-piece lens should be decreased
Answer: Eye-piece lens should be decreased
(3)
Which of the following is used to split white light into different colours?
[A]
Glass slab
[B]
Convex lens
[C]
Concave lens
[D]
Prism
(4)
'Short-sight' in human eye can be corrected by using proper
[A]
convex lens
[B]
concave lens
[C]
cylindrical lens
[D]
bifocal lens
(5)
Which one of the following lenses should be used to correct the defect of astigmatism?
[A]
Cylindrical lens
[B]
Concave lens
[C]
Convex lens
[D]
Bifocal lens
(6)
A mirage occurs because of
[A]
reflection by hot ground
[B]
total internal reflection by layers of air
[C]
interference of light
[D]
diffraction of light
Answer: total internal reflection by layers of air
(7)
A periscope works on the principal of
[A]
refraction
[B]
total internal reflection
[C]
diffraction
[D]
reflection
Answer: total internal reflection
(8)
Which of the following is incorrect?
[A]
A concave mirror can give a magnified virtual image
[B]
A concave mirror can give a magnified real image
[C]
The virtual image given by a concave mirror is inverted
[D]
The real image given by a concave mirror is inverted
Answer: The virtual image given by a concave mirror is inverted
(9)
What would be the number of images formed of an object in two mirrors placed at right angles to each other?
[A]
two
[B]
three
[C]
four
[D]
six
(10)
The head mirror used by E.N.T doctors is -
[A]
Concave
[B]
Convex
[C]
Plane
[D]
Plano-convex
(11)
How far must an object be from a concave mirror if the image formed is to be inverted?
[A]
less than its focal length
[B]
exactly at its focal length
[C]
more than its focal length
[D]
None of the above
Answer: more than its focal length
(12)
How far must a girl stand in front of a concave spherical mirror of radius 120 cm to see an erect image of her face four times its natural size?
[A]
40 cm from the mirror
[B]
45 cm from the mirror
[C]
50 cm from the mirror
[D]
55 cm from the mirror
Answer: 45 cm from the mirror
(13)
The human eye is like a camera and hence it contains a system of lens. The eye lens forms
[A]
a straight or upright, real image of the object on the retina
[B]
an inverted, virtual image of the object on the retina
[C]
an inverted, real image of the object on the retina
[D]
a straight or upright, real image of the object on the iris
Answer: an inverted, real image of the object on the retina
(14)
The ratio of the focal length of the objective to the focal length of the eyepiece is greater than one for
[A]
a microscope
[B]
a telescope
[C]
both microscope and telescope
[D]
neither microscope nor telescope
(15)
Which one among the following is used to make periscope?
[A]
Concave lens
[B]
Concave mirror
[C]
Plane mirror
[D]
None of the above
(16)
What type of a mirror is used in anti-shop-lifting-devices?
[A]
Concave mirror
[B]
Convex mirror
[C]
Plane mirror
[D]
None of the above
(17)
Due to which phenomena the stick if immersed in water appears to be bent?
[A]
Reflection
[B]
Dispersion
[C]
Refraction
[D]
Scattering
(18)
What is the power of concave lens?
[A]
Positive
[B]
Negative
[C]
Both
[D]
None of the above
(19)
In projectors which lenses are used?
[A]
Convex lens
[B]
Concave lens
[C]
Bipolar lens
[D]
Both (a) and (b)
(20)
Due to which phenomena light rays emerging from a cinema machine spread wide on the screen?
[A]
Dispersion
[B]
Diffraction
[C]
Scattering
[D]
Refraction
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