CBSE Questions for Class 12 Medical Physics Ray Optics And Optical Instruments Quiz 7 - MCQExams.com

Match the columns:
i. convex lens    a. presbyopia
ii. concave lensb. cataract
iii. Artificial lensc. myopia
iv. focal lensd. hypermetropia
  • i-c,ii-d,iii-a,iv-b
  • i-d,ii-c,iii-b,iv-a
  • i-b,ii-c,iii-a,iv-d
  • i-a,ii-b-iii-d,iv-c
The refractive defects of the eye can be corrected by _____ :
  • Eye glasses
  • contact lenses
  • Surgical procedures
  • All of the above
Hypermetropia may arise due to _____:
a. Shrinking of the eyeball.
b. Elongation of eyeball.
c. Long focal length of the eye.
d. Excessive curvature of the eye lens.
  • b and c
  • a and c
  • a and d
  • b and d
Which of the following statements are true for presbyopia?
  • Decreased power of accommodation
  • Weak ciliary muscles and reduced flexibility of eye lens
  • Usually occurs with increasing age
  • All of the above
Match the following
List IList II
1Change in curvaturea25 cm
2Relaxed ciliary musclesbCurvature of the lens decreases
3Thick lenscChange in focal length
4Near pointdFocal length increases
  • 1-b, 2-c, 3-a, 4-d
  • 1-c, 2-d, 3-b, 4-a
  • 1-a, 2-c, 3-b, 4-d
  • 1-c, 2-a, 3-d, 4-b
The condition occurring due to gradual decrease in power of accommodation because of ageing is called ____ .
  • Near-sightedness
  • Hypermetropia
  • Presbyopia
  • Cataract
The refractive defects of vision are
a. Myopia                     b. Cataract
c. Hypermetropia        d. Presbyopia
  • a and b
  • a, c and d
  • b and c
  • All of the above
Myopia can be corrected by using a _____.
  • Converging lens
  • Bifocal lens
  • Diverging lens
  • None of the above
Which of the following statements are true for hypermetropia?
a. The near point is farther away from 25cm.
b. The image of the object is formed behind the retina.
c. It arises due to decreased power of accommodation.
d. It can be corrected by the diverging lens.
  • $$b$$ and $$c$$
  • $$c$$ and $$d$$
  • $$a$$ and $$b$$
  • $$a$$ and $$d$$
Refraction occurs due to:
  • Change in direction of light
  • Change in speed of light
  • Change in quality of light
  • All
The angle of incidence of a ray for which the angle of refraction is $$90^{\circ}$$ is called
  • Scattering angle
  • Reflex angle
  • Critical angle
  • Optical angle
There is a small block in the centre C of solid glass sphere of refractive index $$\mu$$. When seen from outside the block will appear to be located :
  • Away from C for all values of $$\mu$$
  • at C for all values of $$\mu$$
  • at C for $$\mu=1.5$$ but away from C for $$\mu \neq 1.5$$
  • at C only for$$ \sqrt{2} \leq\mu\leq 1.5$$
Match the following:

List IList II
1MyopiaaCorrects far vision
2HypermetropiabWeakening of ciliary muscles
3PresbyopiacCorrects near vision
4Concave lensdNear sightedness
5Convex lenseFar sightedness
  • 1-b, 2-c, 3-a, 4-d, 5-e
  • 1-d, 2-e, 3-b, 4-a, 5-c
  • 1-a, 2-c, 3-e, 4-d, 5-b
  • 1-c, 2-e, 3-d, 4-b, 5-a
Fill up the blanks:
a) light sensitive screen of human eye..............
b) near sightedness is corrected by..................
c) hypermetropia is corrected by.................
d) range of vision for a normal eye............
  • a. retina
    b. concave lens
    c. convex lens
    d. $$25cm-$$infinity
  • a. cornea
    b. convex lens
    c. concave lens
    d. $$0-25cm$$
  • a. iris
    b. converging lens
    c. diverging lens
    d. $$0-$$infinity
  • a. sclera
    b. diverging lens
    c convex lens
    d. infinity
The phenomenon of scattering of light by fine particles is called _____ :
  • Snell's law
  • Dispersion effect
  • Law of refraction
  • Tyndall effect
Myopia may arise due to ____ .

a. Elongation of eyeball
b. Shrinking of the eyeball
c. Long focal length of the eye
d. Increased curvature of the eye lens
  • a and b
  • b and c
  • c and d
  • a and d
Why do high rise buildings have a red light on the top of the building?
  • Red light is the least scattered by fine particles
  • Red light can be easily spotted by the pilot
  • Both A and B
  • None 
How does concave lens correct myopia?
  • Increases the curvature of the eye lens
  • Forms the image of the object at the retina
  • Decreases the elongation of the eyeball
  • All of the above
The following conditions are seen in which defect of vision?
a. The vision is clear up to a distance of few meters
b. It may occur due to elongation of eyeball
c. The image of the object is formed in front of the retina
  • Myopia
  • Cataract
  • Presbyopia
  • Hypermetropia
Fill in the blanks
The ray of light bending away from normal is called _____. 
  • Refracted ray
  • Incident ray
  • Emergent ray
  • None of the above
Presbyopia can be corrected with the help of _____ .
  • Bifocal lens
  • Diverging lens
  • Convex lens
  • All of the above
Which of the following are examples of scattering of light?
  • Blue color of the sky
  • Reddening of the sun at sunrise and sunset
  • Color of water in deep seas and oceans
  • All of the above
There is a small black dot at the centre $$C$$ of a solid glass sphere of refractive index $$\mu$$. When seen from outside, comment on the location of the dot.
  • away from $$C$$ for all values of $$\mu$$
  • at $$C$$ for all values of $$\mu$$
  • at $$C$$ for $$\mu = 1.5$$, but away from $$C$$ for $$\mu \neq 1.5$$
  • at $$C$$ only for $$\sqrt {2} \leq \mu \leq 1.5$$
Which phenomena of light makes a pool of water appears to be less deep than it actually is?
  • Reflecion
  • Refraction
  • Diffraction
  • Lateral inversion
Change in the direction of light when it passes from one medium to another is called ............
  • reflection
  • refraction
  • diffraction
  • scattering
Height of the object and height of the image are measured from the:
  • Optical centre
  • Principal axis
  • Principal focus
  • Aperture
Which of the following comes under laws of refraction?
  • Angle of incidence is equal to angle refraction
  • Angle of refraction is greater than angle of incidence
  • Value of $$\dfrac {sin\ i}{sin\ r}$$ is known as refractive index of the medium
  • All
When light travels from air to water there is ...........................
  • Reflection of light
  • Refraction of light
  • Diffraction of light
  • Scattering of light
The incident ray, the normal at the point of incidence and the refracted ray:
  • lie on mutually orthogonal planes
  • lie on mutually parallel planes
  • lie on the same plane
  • lie on different arbitrary planes
For a light ray undergoing refraction, $$\dfrac{sin i}{sin r}=$$
  •  $$\frac{\mu_2}{\mu_1}$$
  • $$1$$, always
  • $$0$$, always
  • none of these
The primary phenomenon in the working of lens is
  • Reflection
  • Refraction
  • Scattering
  • Diffusion
The refractive index of a medium is ______  to the speed of light in the medium.
  • directly proprtional
  • inversely proportional
  • independent
  • exponentially increasing
According to laws of refraction, refraction of light at the boundary between two different regions follow:
  • that the incident ray, the normal at the point of incidence and the refracted ray, all lie in the same plane.
  • that for a given pair of media and given colour of light, the ratio of the sine of angle of incidence to the sine of angle of refraction is constant.
  • both A and B
  • neither A nor B
The refractive index of a medium:
  • is defined with respect to another medium
  • is an absolute constant for a medium
  • depends on the frequency of the light in the medium
  • is more for higher intensity of light ray
Given a trace of light, refractive index of the medium can be found by using:
  • universal Law of light
  • Shell's Law
  • Snell's Law
  • Hooke's Law
Second law of refraction is also called:
  • Shell's Law
  • Snell's Law
  • Hooke's Law
  • none of the above
Light enters from denser to rarer medium. Choose the correct option.
  • Angle of refraction = Angle of incidence
  • Angle of refraction > Angle of incidence
  • Angle of refraction < Angle of incidence
  • Angle of refraction $$\geq$$ Angle of incidence
A man sees a small stationary fish deep in a very clear lake and shoots it accurately. He will
  • hit the fish
  • miss the fish
  • hit but fish will not die
  • may hit or miss depending on the bullet
Due to refraction,
  • Image in the plane mirror is clear
  • Polished black surfaces shine
  • speed of light is constant in all mediums
  • A glass sphere appears attractive
The high focal length convex lens is used in simple microscope.
  • True
  • False
Iris in the human eye controls the light entering it.
  • True
  • False
Why is it advised to use telescope in a clear sky?
  • Less interference between telescope and object.
  • To get better quality of image
  • To reduce the lateral shift in images caused by the environment
  • All of the above
A myopic person cannot see clearly:
  • Near objects
  • Objects placed at the least distance of distinct vision
  • Very far objects
  • None of these
A telescope:
  • converges light
  • diverges light
  • reflects light
  • refracts light
Refraction of light can take place at boundary of
  • Transparent Media
  • Opaque Media
  • Any Medium
  • Rarer Medium
When is the virtual image formed?
  • when the rays of light after reflection or refraction appear to meet at a point
  • when the rays of light after reflection or refraction meet at a point
  • when the rays of light after deflection appear to meet at a point
  • when the lens rays after reflection or refraction meet at a point
A spherical mirror and a thin spherical lens have each a focal length of $$-15$$ cm. The mirror and lens are likely to be :
  • both concave
  • both Convex
  • the mirror is concave and lens is convex
  • the mirror is convex but lens is concave
Which of the following lenses would you prefer to use while reading small letters found in a dictionary?
  • A convex lens of focal length 50 cm
  • A concave lens of focal length 50 cm
  • A convex lens of focal length 5 cm
  • A concave lens of focal length 5 cm
The refractive index of water and glass with respect to air is $$1.3$$ and $$1.5$$ respectively. Then the refractive index of glass with respect to water is
  • $$\dfrac{2.6}{1.5}$$
  • $$\dfrac{1.5}{2.6}$$
  • $$\dfrac{1.3}{1.5}$$
  • $$\dfrac{1.5}{1.3}$$
Which of the below is one of the laws of refraction?
  • The incident ray, the normal and the refracted ray, all lie in a different plane.
  • The incident ray, the normal and the refracted ray, all lie in the same plane.
  • The incident ray, the normal and the refracted ray, all lie in opposite plane.
  • The incident ray and the refracted ray, both lie in a plane.
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