If 'A' is the angle of a prism, 'i' is angle of incidence , 'e' is angle of emergence then at minimum angle of deviation 'Dm 'of the light incident on the prism,__________.

'i' + 'e' becomes equal to 'Dm'

A transparent cube of side d, made of a material of refractive index μ2, is immersed in a liquid of refractive index μ1 (μ1 < μ2). A ray is incident on the face AB at an angle θ (shown in the figure). Total internal reflection takes place at point E on the face BC.Then θ must satisfy:

\({\rm{\theta }} > {\rm{si}}{{\rm{n}}^{ - 1}}\frac{{{{\rm{\mu }}_1}}}{{{{\rm{\mu }}_2}}}\)

\({\rm{\theta }} < {\rm{si}}{{\rm{n}}^{ - 1}}\frac{{{{\rm{\mu }}_1}}}{{{{\rm{\mu }}_2}}}\)

\({\rm{\theta }} > {\rm{si}}{{\rm{n}}^{ - 1}}\sqrt {\frac{{{\rm{\mu }}_2^2}}{{{\rm{\mu }}_1^2}} - 1} \)

\({\rm{\theta }} < {\rm{si}}{{\rm{n}}^{ - 1}}\sqrt {\frac{{{\rm{\mu }}_2^2}}{{{\rm{\mu }}_1^2}} - 1} \)

\({\rm{\theta }} > {\rm{si}}{{\rm{n}}^{ - 1}}\frac{{{{\rm{\mu }}_1}}}{{{{\rm{\mu }}_2}}}\)

A lens has a power of +2.0 Dioptre, Which one of the following statements about the lens is true?

The lens is concave and has a focal length of 2.0 metre

The lens is concave and has a focal length of 0.5 metre

The lens is convex and has a focal length of 2.0 metre

The lens is convex and has a focal length of 0.5 metre

The lens is concave and has a focal length of 2.0 metre

How will the light rays passing from a glass prism into air bend?

Almost at 90 degrees with normal

A calcite crystal has been placed on a black dot on a piece of white sheet and then rotated. On looking though the calcite crystal from above, we can see:

One black rotating about the other stationary dot

A ray of light passing through the first principal focus of a convex lens __________ after refraction.

passes through the second principal focus

emerges parallel to the principal axis

passes through the second principal focus

passes through the center of curvature

A converging lens is used to form an image on a screen. When the upper half of the lens is covered by an opaque screen

half of the image will disappear

image will not form on the screen

intensity of image will increase

intensity of image will decrease

A converging lens of focal length f is placed in contact with a diverging lens of focal length 3f. The combination is

A diverging lens of focal length 3f/2

A converging lens of focal length 2f

A diverging lens of focal length 3f

A converging lens of focal length 3f/2

A ray of light passing through the optical centre of a convex lens ___________ after refraction.

passe s through the second principal focus

passes through the center of curvature

becomes parallel to the principal axis

Choose the wrong statement.

A concave mirror can form a magnified real image.

A concave mirror can form a magnified virtual image.

A convex mirror can form a diminished virtual image.

A convex mirror can form a diminished real image.

An achromatic combination of lenses produce

Images unaffected by variation of a refractive index with wavelength

A ray of light passes from glass of refractive index 1.6 to air. The angle of incidence for which the angle of refraction is twice the angle of incidence is

\({\sin ^{ - 1}}\left( {5/8} \right)\)

\({\sin ^{ - 1}}\left( {4/5} \right)\)

\({\sin ^{ - 1}}\left( {3/5} \right)\)

\({\sin ^{ - 1}}\left( {5/8} \right)\)

\({\sin ^{ - 1}}\left( {2/5} \right)\)

A ray parallel to the principal axis incident on a convex mirror after reflection ____________.

becomes parallel to the principal axis

deviates in such a way that when projected backwards passes through the focus

becomes parallel to the principal axis

245 + Mcqs in Wave Optics Page 2 McqOptions

51.	_______ is located behind a convex mirror.
A.	A ray
B.	The focal point
C.	A real image
D.	The object
Answer» C. A real image

Discussion

52.	If 'A' is the angle of a prism, 'i' is angle of incidence , 'e' is angle of emergence then at minimum angle of deviation 'Dm 'of the light incident on the prism,__________.
A.	'i' becomes equal to 'e'
B.	'i' + 'e' becomes equal to 'A'
C.	'i' + 'e' becomes equal to 'Dm'
D.	'Dm ' becomes equal to 'A'
Answer» B. 'i' + 'e' becomes equal to 'A'

Discussion

53.	If the image of an object having length x1 with convex mirror has length x2, then
A.	x1 > x2
B.	x1 = x2
C.	\(x_1 \dfrac{<}{>} x_2\)
D.	x1 < x2
Answer» B. x1 = x2

Discussion

54.	In case of compound microscope which of the following statements is/are correct?1) The focal length of eye piece is larger than the focal length of the objective2) The focal length of the eye piece is smaller than the focal length of the objective3) The image produced in a normal optical microscope is real4) The image produced in a normal optical microscope is virtual
A.	1 only
B.	1 and 4
C.	2 and 3
D.	2 and 4
Answer» C. 2 and 3

Discussion

55.	If an object is placed 20 cm in front of a convex lens of focal length 7.5 cm then find the position of the image (in cm).
A.	24
B.	30
C.	12
D.	15
Answer» D. 15

Discussion

56.	A ray of light is moving from air into medium. If the angle of incidence in air is 45° and angle of refraction is 30°, then find the refractive index of the medium.
A.	\(\sqrt 2 \)
B.	\(\sqrt 5 \)
C.	\(\sqrt 4\)
D.	\(\sqrt 3\)
Answer» B. \(\sqrt 5 \)

Discussion

57.	If a spherical mirror is immersed in a liquid, its focal length will
A.	decrease
B.	depend on the nature of liquid
C.	increase
D.	remain unchanged
Answer» E.

Discussion

58.	Marbles kept in water look enlarged because water acts as a
A.	Concave lens
B.	Convex lens
C.	Magnifying lens
D.	Both B & C
Answer» E.

Discussion

59.	A transparent cube of side d, made of a material of refractive index μ2, is immersed in a liquid of refractive index μ1 (μ1 < μ2). A ray is incident on the face AB at an angle θ (shown in the figure). Total internal reflection takes place at point E on the face BC.Then θ must satisfy:
A.	\({\rm{\theta }} < {\rm{si}}{{\rm{n}}^{ - 1}}\frac{{{{\rm{\mu }}_1}}}{{{{\rm{\mu }}_2}}}\)
B.	\({\rm{\theta }} > {\rm{si}}{{\rm{n}}^{ - 1}}\sqrt {\frac{{{\rm{\mu }}_2^2}}{{{\rm{\mu }}_1^2}} - 1} \)
C.	\({\rm{\theta }} < {\rm{si}}{{\rm{n}}^{ - 1}}\sqrt {\frac{{{\rm{\mu }}_2^2}}{{{\rm{\mu }}_1^2}} - 1} \)
D.	\({\rm{\theta }} > {\rm{si}}{{\rm{n}}^{ - 1}}\frac{{{{\rm{\mu }}_1}}}{{{{\rm{\mu }}_2}}}\)
Answer» D. \({\rm{\theta }} > {\rm{si}}{{\rm{n}}^{ - 1}}\frac{{{{\rm{\mu }}_1}}}{{{{\rm{\mu }}_2}}}\)

Discussion

60.	Find the focal length (in cm) of a convex lens if object is placed at 10 cm from the lens and image is obtained at 50 cm from the lens on the same side?
A.	12.5
B.	25
C.	10
D.	7.5
Answer» B. 25

Discussion

61.	A convex lens (of focal length 20 cm) and a concave mirror, having their principal axes along the same lines, are kept 80 cm apart from each other. The concave mirror is to the right of the convex lens. When an object is kept at a distance of 30 cm to the left of the convex lens, its image remains at the same position even if the concave mirror is removed. The maximum distance of the object for which this concave mirror, by itself would produce a virtual image would be:
A.	30 cm
B.	25 cm
C.	10 cm
D.	20 cm
Answer» D. 20 cm

Discussion

62.	A lens has a power of +2.0 Dioptre, Which one of the following statements about the lens is true?
A.	The lens is concave and has a focal length of 0.5 metre
B.	The lens is convex and has a focal length of 2.0 metre
C.	The lens is convex and has a focal length of 0.5 metre
D.	The lens is concave and has a focal length of 2.0 metre
Answer» D. The lens is concave and has a focal length of 2.0 metre

Discussion

63.	How will the light rays passing from a glass prism into air bend?
A.	Almost at 90 degrees with normal
B.	Towards the normal
C.	Away from the normal
D.	As the normal
Answer» D. As the normal

Discussion

64.	A calcite crystal has been placed on a black dot on a piece of white sheet and then rotated. On looking though the calcite crystal from above, we can see:
A.	One black rotating about the other stationary dot
B.	two stationary black dots
C.	one black dot only
D.	two rotating black dots
Answer» B. two stationary black dots

Discussion

65.	In a Young's double slit experimental set-up, interference fringe pattern has been obtained with sodium light. If the entire experimental set-up were displaced from air and then immersed in clear water, contained in a suitable transparent tank, then the fringe pattern will likely ____________.
A.	remain unchanged
B.	be enlarged significantly
C.	shrink considerably
D.	disappear completely
Answer» D. disappear completely

Discussion

66.	If 'c' is the velocity of light in free space, the time taken by light to travel a distance x in medium of refractive index μ is given by
A.	μxc
B.	\(\frac {\mu x}{c}\)
C.	\(\frac {\mu c}{x}\)
D.	\(\frac {x}{\mu c}\)
Answer» C. \(\frac {\mu c}{x}\)

Discussion

67.	Equation of travelling wave on a stretched string of linear density 5 g/m isy = 0.03 sin (450t – 9x),where distance and time are measured in SI units. The tension in the string is
A.	5 N
B.	12.5 N
C.	7.5 N
D.	10 N
Answer» C. 7.5 N

Discussion

68.	A ray of light passing through the first principal focus of a convex lens __________ after refraction.
A.	emerges without any deviation
B.	emerges parallel to the principal axis
C.	passes through the second principal focus
D.	passes through the center of curvature
Answer» C. passes through the second principal focus

Discussion

69.	A converging lens is used to form an image on a screen. When the upper half of the lens is covered by an opaque screen
A.	half of the image will disappear
B.	image will not form on the screen
C.	intensity of image will increase
D.	intensity of image will decrease
Answer» E.

Discussion

70.	In a concave mirror if x1 and x2 are the distances of object and its image respectively from the focus, then the focal length of the mirror is -
A.	x1x2
B.	\(\frac{(x_1+x_2)}{2}\)
C.	\(\sqrt{x_1x_2}\)
D.	\(\frac{x_1x_2}{x_1+x_2}\)
Answer» D. \(\frac{x_1x_2}{x_1+x_2}\)

Discussion

71.	A wavefront is defined as a surface of ______________ phase
A.	increasing
B.	constant
C.	decreasing
D.	time variable
Answer» C. decreasing

Discussion

72.	A converging lens of focal length f is placed in contact with a diverging lens of focal length 3f. The combination is
A.	A diverging lens of focal length 3f/2
B.	A converging lens of focal length 2f
C.	A diverging lens of focal length 3f
D.	A converging lens of focal length 3f/2
Answer» E.

Discussion

73.	Radius of curvature of a concave mirror is 40 cm. An object of height 1 cm is placed at a distance of 30 cm from the mirror. Find the height of the image.
A.	3 cm
B.	2 cm
C.	1 cm
D.	1.5 cm
Answer» C. 1 cm

Discussion

74.	Find the minimum angle of deviation of a thin prism of 5° angle of prism and 1.5 refractive index?
A.	7.5°
B.	2.5°
C.	6.5°
D.	3.5°
Answer» C. 6.5°

Discussion

75.	A stone placed at the bottom, of water tank appears raised by 80 cm. If refractive index of water is 4/3. The actual depth of water in tank.
A.	480 cm
B.	320 cm
C.	400 cm
D.	200 cm
Answer» C. 400 cm

Discussion

76.	In an optical instrument like a telescope, the combination of field lens and eye lens forms
A.	an objective
B.	compound eye-piece
C.	magnifier
D.	None of the above
Answer» C. magnifier

Discussion

77.	A plane is inclined at an angle α = 30° with respect to the horizontal. A particle is projected with a speed u = 2 ms-1, from the base of the plane, making an angle θ = 15° with respect to the plane as shown in the figure. The distance from the base, at which the particle hits the plane is close to:[Take g = 10 ms-2]
A.	20 cm
B.	18 cm
C.	26 cm
D.	14 cm
Answer» B. 18 cm

Discussion

78.	Bending of light as it passes from one medium to another is called
A.	reflection
B.	diffraction
C.	refraction
D.	deflection
Answer» D. deflection

Discussion

79.	How much magnification can be obtained at near point 25 cm by using a convex lens of focal length 10 cm?
A.	1.5
B.	4.5
C.	3.5
D.	6
Answer» D. 6

Discussion

80.	A ray of light passing through the optical centre of a convex lens ___________ after refraction.
A.	passe s through the second principal focus
B.	passes through the center of curvature
C.	becomes parallel to the principal axis
D.	emerges without any deviation
Answer» E.

Discussion

81.	A particle A of mass ‘m’ and charge ‘q’ is accelerated by a potential difference of 50 V. Another particle B of mass ‘4m’ and charge ‘q’ is accelerated by a potential difference of 2500 V. The ratio of de-Broglie wavelengths \(\frac{{{{\rm{\lambda }}_{\rm{A}}}}}{{{{\rm{\lambda }}_{\rm{B}}}}}\) is close to
A.	4.47
B.	10
C.	0.07
D.	14.14
Answer» E.

Discussion

82.	Choose the wrong statement.
A.	A concave mirror can form a magnified real image.
B.	A concave mirror can form a magnified virtual image.
C.	A convex mirror can form a diminished virtual image.
D.	A convex mirror can form a diminished real image.
Answer» E.

Discussion

83.	A convex lens produces a double size real image when an object is placed at a distance of 18 cm from it. When should the object be placed in front of convex lens to produce a triple size real image?
A.	9 cm
B.	12 cm
C.	16 cm
D.	6 cm
Answer» D. 6 cm

Discussion

84.	A load of mass M kg is suspended from a steel wire of length 2m and radius 1.0mm in Searle’s apparatus experiment. The increase in length produced in the wire is 4.0mm. Now, the load is fully immersed in a liquid of relative density 2. The relative density of the material of load is 8. The new value of increase in length of the steel wire is
A.	Zero
B.	5.0 mm
C.	4.0 mm
D.	3.0 mm
Answer» E.

Discussion

85.	An achromatic combination of lenses produce
A.	Images in black and white
B.	Coloured images
C.	Images unaffected by variation of a refractive index with wavelength
D.	highly enlarged image
Answer» D. highly enlarged image

Discussion

86.	A plano-convex lens of refractive index μ1 and focal length f1 is kept in contact with another plano-concave lens of refractive index μ2 and focal length f2. If the radius of curvature of their spherical faces is R each and f1 = 2f2, then μ1 and μ2 are related as
A.	3μ2 – 2μ1 = 1
B.	2μ2 – μ1 = 1
C.	2μ1 – μ2 = 1
D.	μ1 + μ2 = 3
Answer» D. μ1 + μ2 = 3

Discussion

87.	A lady is standing in front of plane mirror at a distance of 1 m from it. She walks 60 cm towards the mirror. The distance of her image now from herself (ignored the thickness of the mirror) is
A.	40 cm
B.	60 cm
C.	80 cm
D.	120 cm
Answer» D. 120 cm

Discussion

88.	______ is used to describe the information about the hue and saturation of a color.
A.	Phosphorescence
B.	Sharpness
C.	Chrominance
D.	Luminance
Answer» D. Luminance

Discussion

89.	A 20 cm long tube containing 15% sugar solution rotates the plane of polarization of light by 21°. The specific rotation of sugar solution is:
A.	64°
B.	70°
C.	58°
D.	49°
Answer» C. 58°

Discussion

90.	A monochromatic ray of light is incident on a medium at an angle of 60°. The reflecting rays is found to be completely polarized. Then the refractive index of the medium is nearly
A.	1.33
B.	1.5
C.	1.73
D.	1.41
Answer» D. 1.41

Discussion

91.	A crown glass prism with refracting angle 6o is to be achromatized for red and blue light with a flint glass prism. The angle of the flint glass should be (Given μr = 1.513, μb = 1.523 for crown glass and μr = 1.645, μb = 1.665 for flint glass)
A.	1.5o
B.	2.4o
C.	3o
D.	4.5o
Answer» D. 4.5o

Discussion

92.	A ray of light passes from glass of refractive index 1.6 to air. The angle of incidence for which the angle of refraction is twice the angle of incidence is
A.	\({\sin ^{ - 1}}\left( {4/5} \right)\)
B.	\({\sin ^{ - 1}}\left( {3/5} \right)\)
C.	\({\sin ^{ - 1}}\left( {5/8} \right)\)
D.	\({\sin ^{ - 1}}\left( {2/5} \right)\)
Answer» C. \({\sin ^{ - 1}}\left( {5/8} \right)\)

Discussion

93.	Intensity of light at a point on the screen due to two coherent sources each generating an intensity Io at the point and reaching the point at a phasedifference of φ is given by _____________.
A.	I = Iocos2(φ/2)
B.	I = 4Iocos2φ
C.	I = Iocos2φ
D.	I = 4Iocos2(φ/2)
Answer» E.

Discussion

94.	In a Newton’s rings experiment, light of wavelength λ and a lens of radius of curvature R are used. The radius of 5th bright ring is n times the radius of the 2nd bright ring. Then n is:
A.	\(\sqrt 2\)
B.	\(\sqrt 3\)
C.	\(\sqrt 5\)
D.	\(\sqrt 7\)
Answer» C. \(\sqrt 5\)

Discussion

95.	A light ray strikes a reflective plane surface at an angle of 56° with the surface. The angle of reflection will be
A.	34°
B.	56°
C.	68°
D.	90°
Answer» B. 56°

Discussion

96.	In absence of the earth's atmosphere, the sky will appear
A.	black
B.	red
C.	green
D.	blue
Answer» B. red

Discussion

97.	An object is first placed at a distance 24 cm from the lens and then at a distance of 16 cm from the lens. The magnification of the image formed is same in both the cases. The focal length of the lens is -
A.	22 cm
B.	18 cm
C.	20 cm
D.	8 cm
Answer» D. 8 cm

Discussion

98.	If an object is at infinity, what will be the position of an image formed due to convex lens?
A.	Beyond F2
B.	On C2
C.	At infinity
D.	At the focal point
Answer» E.

Discussion

99.	A progressive wave travelling along the positive x-direction is represented by y(x, t) = Asin(kx – ω t + ϕ). Its snapshot at t = 0 is given in the figure.For this wave, the phase ϕ is:
A.	\( - \frac{\pi }{2}\)
B.	π
C.	0
D.	\(\frac{\pi }{2}\)
Answer» C. 0

Discussion

100.	A ray parallel to the principal axis incident on a convex mirror after reflection ____________.
A.	retraces the path it came from
B.	deviates in such a way that when projected backwards passes through the focus
C.	becomes parallel to the principal axis
D.	passes through the focus
Answer» C. becomes parallel to the principal axis

Discussion

Explore topic-wise MCQs in UPSEE.

_______ is located behind a convex mirror.

If 'A' is the angle of a prism, 'i' is angle of incidence , 'e' is angle of emergence then at minimum angle of deviation 'Dm 'of the light incident on the prism,__________.

If the image of an object having length x1 with convex mirror has length x2, then

If an object is placed 20 cm in front of a convex lens of focal length 7.5 cm then find the position of the image (in cm).

A ray of light is moving from air into medium. If the angle of incidence in air is 45° and angle of refraction is 30°, then find the refractive index of the medium.

If a spherical mirror is immersed in a liquid, its focal length will

Marbles kept in water look enlarged because water acts as a

A transparent cube of side d, made of a material of refractive index μ2, is immersed in a liquid of refractive index μ1 (μ1 < μ2). A ray is incident on the face AB at an angle θ (shown in the figure). Total internal reflection takes place at point E on the face BC.Then θ must satisfy:

Find the focal length (in cm) of a convex lens if object is placed at 10 cm from the lens and image is obtained at 50 cm from the lens on the same side?

A lens has a power of +2.0 Dioptre, Which one of the following statements about the lens is true?

How will the light rays passing from a glass prism into air bend?

A calcite crystal has been placed on a black dot on a piece of white sheet and then rotated. On looking though the calcite crystal from above, we can see:

In a Young's double slit experimental set-up, interference fringe pattern has been obtained with sodium light. If the entire experimental set-up were displaced from air and then immersed in clear water, contained in a suitable transparent tank, then the fringe pattern will likely ____________.

If 'c' is the velocity of light in free space, the time taken by light to travel a distance x in medium of refractive index μ is given by

Equation of travelling wave on a stretched string of linear density 5 g/m isy = 0.03 sin (450t – 9x),where distance and time are measured in SI units. The tension in the string is

A ray of light passing through the first principal focus of a convex lens __________ after refraction.

A converging lens is used to form an image on a screen. When the upper half of the lens is covered by an opaque screen

In a concave mirror if x1 and x2 are the distances of object and its image respectively from the focus, then the focal length of the mirror is -

A wavefront is defined as a surface of ______________ phase

A converging lens of focal length f is placed in contact with a diverging lens of focal length 3f. The combination is

Radius of curvature of a concave mirror is 40 cm. An object of height 1 cm is placed at a distance of 30 cm from the mirror. Find the height of the image.

Find the minimum angle of deviation of a thin prism of 5° angle of prism and 1.5 refractive index?

A stone placed at the bottom, of water tank appears raised by 80 cm. If refractive index of water is 4/3. The actual depth of water in tank.

In an optical instrument like a telescope, the combination of field lens and eye lens forms

Bending of light as it passes from one medium to another is called

How much magnification can be obtained at near point 25 cm by using a convex lens of focal length 10 cm?

A ray of light passing through the optical centre of a convex lens ___________ after refraction.

Choose the wrong statement.

A convex lens produces a double size real image when an object is placed at a distance of 18 cm from it. When should the object be placed in front of convex lens to produce a triple size real image?

An achromatic combination of lenses produce

A plano-convex lens of refractive index μ1 and focal length f1 is kept in contact with another plano-concave lens of refractive index μ2 and focal length f2. If the radius of curvature of their spherical faces is R each and f1 = 2f2, then μ1 and μ2 are related as

A lady is standing in front of plane mirror at a distance of 1 m from it. She walks 60 cm towards the mirror. The distance of her image now from herself (ignored the thickness of the mirror) is

______ is used to describe the information about the hue and saturation of a color.

A 20 cm long tube containing 15% sugar solution rotates the plane of polarization of light by 21°. The specific rotation of sugar solution is:

A monochromatic ray of light is incident on a medium at an angle of 60°. The reflecting rays is found to be completely polarized. Then the refractive index of the medium is nearly

A crown glass prism with refracting angle 6o is to be achromatized for red and blue light with a flint glass prism. The angle of the flint glass should be (Given μr = 1.513, μb = 1.523 for crown glass and μr = 1.645, μb = 1.665 for flint glass)

A ray of light passes from glass of refractive index 1.6 to air. The angle of incidence for which the angle of refraction is twice the angle of incidence is

Intensity of light at a point on the screen due to two coherent sources each generating an intensity Io at the point and reaching the point at a phasedifference of φ is given by _____________.

In a Newton’s rings experiment, light of wavelength λ and a lens of radius of curvature R are used. The radius of 5th bright ring is n times the radius of the 2nd bright ring. Then n is:

A light ray strikes a reflective plane surface at an angle of 56° with the surface. The angle of reflection will be

In absence of the earth's atmosphere, the sky will appear

An object is first placed at a distance 24 cm from the lens and then at a distance of 16 cm from the lens. The magnification of the image formed is same in both the cases. The focal length of the lens is -

If an object is at infinity, what will be the position of an image formed due to convex lens?

A progressive wave travelling along the positive x-direction is represented by y(x, t) = Asin(kx – ω t + ϕ). Its snapshot at t = 0 is given in the figure.For this wave, the phase ϕ is:

A ray parallel to the principal axis incident on a convex mirror after reflection ____________.