CBSE Questions for Class 10 Physics Light Reflection And Refraction Quiz 11 - MCQExams.com

In a car a rear view mirror having a radius of curvature 1.50 m forms a virtual image of a bus located 10.0 m from the mirror. The factor by which the mirror magnifies the size of the bus is close to
  • 0.06
  • 0.07
  • 0.08
  • 0.09
From the understanding of cartesian sign convention for reflection by spherical mirror, students took part in group discussion for $$FA-I$$ in classroom. Who is wrong in the group discussion?
Alpesh : All the distances are measured from the pole of a mirror parallel to the principal axis.
Beena: The distance measured in the direction of incident ray are taken positive.
Champak: The height measured upward and perpendicular to principal axis is taken negative.
Daksha : The height measured downward and perpendicular to principal axis is taken as positive.
  • Champak and Daksha
  • Only Champak
  • Alpesh and Beena
  • Only Daksha
The magnification produced by a mirror is $$+\dfrac{1}{3}.$$ Then the mirror is a ____________.
  • Concave mirror
  • Convex mirror
  • Plane mirror
  • plano convex mirror
Choose the correct answer from the alternatives given.
There is certain material developed in laboratories which have a negative refractive index. A ray incident from the air (medium 1) into such a medium (medium 2) shall follow a path given by:
The image of the needle placed 45 cm from a lens is formed on a screen placed 90 cm on the other side of the lens. The displacement of the image, if the needle is moved by 5.0 cm away from the lens is 
  • 10 cm, toward the lens
  • 15 cm, away from the lens
  • 15 cm, towards the lens
  • 10 cm, away from the lens
A convex mirror forms an image one-fourth the size of the object. If object is at a distance of $$0.5\ m$$ from mirror the focal length of the mirror is
  • $$0.16\ m$$
  • $$-1.5\ m$$
  • $$0.4\ m$$
  • $$-0.4\ m$$
Refraction of the light from the air to glass and from air to water are shown in the figure (i) and figure (ii) below. The value of an angle $$\theta$$ in the case of refraction as shown in the figure (iii) will be
952203_d1bd6a383900447c82ba5d8e8a4a0035.png
  • $$30$$
  • $$35$$
  • $$60$$
  • $$41$$
Magnification produced is +$$\dfrac { 1 }{ 3 }$$, then what kind of mirror it is?
  • concave mirror
  • convex mirror
  • opaque mirror
  • plane mirror
A ray $$R_{1}$$ is incident on the plane surface of the glass slab (kept in air) of refractive index $$\sqrt {2}$$ at an angle of incidence equal to the critical angle for this air glass system. The refracted ray $$R_{2}$$ undergoes partial reflection and refraction at the other surface. The angle between reflected ray $$R_{3}$$ and the refracted ray $$R_{4}$$ at that surface is :
766780_e83c12f919e94b31b1984d5e7ad871bc.png
  • $$45^{\circ}$$
  • $$135^{\circ}$$
  • $$105^{\circ}$$
  • $$75^{\circ}$$
An object is placed at a distance of 1.5 m from a screen and a convex lens is interposed between them. The magnification produced isThe focal length of the lens is then
  • 1 m
  • 0.5 m
  • 0.24 m
  • 2 m
Refraction of light from air to glass and from air to water are shown in figure (i) and figure (ii) below. The value of the angle $$\theta$$ in the case of refraction as shown in figure (iii) will be 


942211_6b90c2a02cc24a1392b5e352ac352c01.png
  • $$30^o$$
  • $$35^o$$
  • $$60^o$$
  • $$41^o$$
A convex lens of focal length $$f$$ produces a real image $$\mu$$ times the size of an object, Then what is the distance of the object from the lens? 
  • $$\left( \mu -1 \right) f$$
  • $$\left( \mu +1 \right) f$$
  • $$\cfrac { \left( \mu -1 \right) f }{ \mu } $$
  • $$\cfrac { \left( \mu +1 \right) f }{ \mu } $$
The distance between an object and its doubly magnified image by a concave mirror is: [ Assume $$f$$ = focal length]
  • $$ 3 f/2 $$
  • $$2 f/3 $$
  • $$3f$$
  • Depends on whether the image is real or virtual.
For an isosceles prism of angle $$A$$ and refractive index $$\mu$$, it is found that the angle of minimum deviation
$$\delta _{m}=A$$. Which of the following option is/are correct?
  • At minimum deviation, the incident angle $$r_{1}$$ and the refracting surface are related by $$r_{1}=(i_{1}/2)$$.
  • For this prism the refractive index $$\mu$$ at the angle of prism $$A$$ are related as $$A=\dfrac {1}{2} \cos^{-1}(\mu/2)$$.
  • For this prism, the emergent ray at the second surface will be tangential to the surface when the angle of incidence at the first surface is $$i_{ 1 }=\sin ^{ -1 } \left[ \sin { A } \sqrt { 4\cos ^{ 2 }{ \dfrac { A }{ 2 } } -1-\cos { A } } \right] $$.
  • for the angle of incidence $$I_{1}=A$$,the ray inside the prism is parallel to the base of the prism.
An object of length $$6\ cm$$ is placed on the principle axis of a concave mirror of focal length $$f$$ at a distance of $$4\ f$$. The length of the image will be
  • -$$2\ cm$$
  • $$12\ cm$$
  • $$4\ cm$$
  • $$1.2\ cm$$
A bulb is located on a wall. Its image is to be obtained on a parallel wall with the help of convex lens. If the distance between parallel walls is $$D$$ then required focal length of lens placed in middle between the walls is :
  • only $$\dfrac { D}{ 4 } $$
  • only $$\dfrac { D }{ 2 } $$
  • More than $$\dfrac { D }{ 4 } $$ but less than $$\dfrac { D }{ 2 } $$
  • less than or equal to $$\dfrac { D }{ 4 } $$
An object placed in front of a concave mirror of  focal length $$0.15\ m$$ produces a virtual image, which is twice the size of the object. The position of the object with respect to the mirror is :
  • $$-5.5\ cm$$
  • $$-6.5\ cm$$
  • $$- 7.5\ cm$$
  • $$- 8.5\ cm$$
The magnification of plane mirror is always - 
  • $$ <1 $$
  • $$ > 1 $$
  • $$ = 1 $$
  • Zero
An infinitely long rod lies along the axis of a concave mirror of focal length l. The near end of the rod is at distance u $$>$$ f from the mirror. Its image will have a length?
  • $$\dfrac{uf}{u-f}$$
  • $$\dfrac{uf}{u+f}$$
  • $$\dfrac{f^1}{u-f}$$
  • $$\dfrac{f^2}{u-f}$$
A pin of length $$2\ cm$$ along the principle axis of a converging lens, the centre being at a distance of $$11\ cm$$ from the lens. The focal length of the lens is $$6\ cm$$. Find the size of the image ?
  • $$3\ cm$$
  • $$2.4\ cm$$
  • $$10\ cm$$
  • $$5\ cm$$
A ray of light travels from water to glass as shown below. The refractive index of water is $$1.3$$ and the refractive index of glass is $$1.5$$. What is the angle of refraction ?
1210219_d4ef5368eed940678645fa8f508ac5dc.png
  • $$30.7^{o}$$
  • $$35.3^{o}$$
  • $$41.7^{o}$$
  • $$48.6^{o}$$
For a mirror linear magnification m come out to be +What conclusions can be drawn from this ?
  • Mirror is concave
  • Mirror can be convex or concave but it cannot be plane
  • Object lies between pole and focus
  • Object lies beyond focus
Which mirror is to be used to obtain a parallel beam of light from a point source?
  • Plane mirror
  • Concave mirror
  • convex mirror
  • None of these.
A film projector magnifies a film of area $$100 $$ square centimeter on screen. If linear magnification is $$4$$ then area of magnified image on screen will be-
  • $$1600 sq. cm$$
  • $$800 sq. cm$$
  • $$400 sq. cm$$
  • $$200 sq. cm$$
The image formed by a convex mirror of focal length $$30\ cm$$ is a quarter of the size of the object. The distance of the object from the mirror is 
  • $$30\ cm$$
  • $$90\ cm$$
  • $$120\ cm$$
  • $$60\ cm$$
The focal length of a concave mirror is $$50 \ cm$$. Where should an object be placed, so that its image is two times and is inverted
  • $$75 \ cm$$
  • $$60 \ cm$$
  • $$125 \ cm$$
  • $$50 \ cm$$
An object is placed at a distance of $$16 cm$$ from a convex mirror of focal length $$20 cm$$, the position of image with its nature is 
  • Virtual, erect behind the mirror at 8.9 cm
  • Virtual, erect behind the mirror at 89 cm
  • Real, erect behind the mirror at 8.9 cm
  • Virtual, inverted behind the mirror at 89 cm
A real object is placed at $$20 \ cm$$ from a concave mirror of focal length $$5 \ cm$$. Find the magnification.
  • $$3$$
  • $$-3$$
  • $$\cfrac{1}{3}$$
  • $$-\cfrac{1}{3}$$
A ray of light is incident on the surface of separating two transparent medium at an angle $$45^0$$ and is refracted in medium at an angle $$30^0$$. Velocity of light in the medium will be...
  • $$3.8 \times 10^8 \ m/s$$ 
  • $$3.38 \times 10^8 \ m/s$$ 
  • $$2.12 \times 10^8 \ m/s$$ 
  • $$1.5 \times 10^8 \ m/s$$ 
A glass containing a liquid appears to be half filled when viewed from top, if it is actually two-thirds filled. The refractive index of liquid is
  • $$\cfrac 7 6$$
  • $$\cfrac 5 4$$
  • $$\cfrac 4 3$$
  • $$2$$
For water $$\mu = \dfrac{4}{3}$$ and the velocity of light in vacuum is $$3 \times 10^8 m/s$$, the time taken for light to travel a distance of $$450\ m$$ in water will be.
  • $$2 \mu s$$
  • $$1.5 \mu s$$
  • $$1 \mu s$$
  • $$3 \mu s$$
A ray of light is travelling through a medium of refractive index  $$\sqrt { 2   }$$ with respect to air. When it is incident on the surface making an angle $${ 45 }^{ o }$$ with the surface, which of the following will take place?(Medium to which refracted ray travels is air)
  • angle of refraction will be $${ 45 }^{ o }$$.
  • angle of refraction will be $${ 90 }^{ o }$$
  • The ray will be reflected internally
  • None of the above
A convex lens is placed somewhere in between an object and a screen. The distance between the object and screen is $$48\ cm$$. If the numerical value of the magnification produced by the lens is $$3$$, the focal length of the lens is :
  • $$16\ cm$$
  • $$4.5\ cm$$
  • $$12\ cm$$
  • $$9\ cm$$
A ray of light is incident on a glass at an angle of $$60^o$$. What would be the refractive index of glass, if reflected and refracted rays are perpendicular to each other ?
  • $$\sqrt{3}$$
  • $$\dfrac{3}{2}$$
  • $$\dfrac{\sqrt{3}}{2}$$
  • $$\dfrac{1}{2}$$
The refractive indices of glass and water are 3/ 2 and 4/ 3 respectively. The refractive index of glass with respect to water is

  • 2
  • 8/9
  • 9/8
  • 5/3
Monochromatic light is refracted from air into the glass of refractive index $$ \mu $$. The ratio of the wavelength of incident and refracted waves is

  • 1:$$ \mu $$
  • 1:$$ \mu $$$$ ^{2} $$
  • $$ \mu $$ :1
  • 1:1
The image formed by a convex mirror of focal length 30 cm is a quarter of the size of the object. The distance of the object from the mirror is-

  • $$30cm$$
  • $$90 cm$$
  • $$120 cm$$
  • $$60 cm$$
The ray of light emerging out of glass slab is always parallel to the incident ray.
  • True
  • False
$${ n }_{ 12 }\times{ n }_{ 21 },$$ in simplest from is
  • 1
  • 2
  • 0
  • 4
Two objects A and B when placed in placed in turn in front of a concave mirror of focal length 7.5 cm give images of equal size. If A is three times the size of B and is placed 30 cm from the mirror, find the distance of B from the mirror.
  • -15 cm
  • 25 cm
  • -17.5 cm
  • -11 cm
Refractive index of a rectangular glass slab is  $$\mu = \sqrt { 3 }.$$  A light ray incident at an angle  $$60 ^ { \circ }$$  is displaced laterally through  $$2.5  { cm } .$$  Distance travelled by light in the slab is
  • $$4 cm$$
  • $$5 cm$$
  • $$2.5\sqrt { 3 } { cm }$$
  • $$3 cm$$
A thin glass (refractive index 1.5) lens has optical power of -5D in air.Its optical power in a liquid medium with refractive index 1.6 will be: 
  • -1D
  • 1 D
  • 25 D
  • -25 D
The refractive index of material of a prism of angles $$45^{\circ}, -45^{\circ}$$, and $$-90^{\circ}$$ is $$1.5$$. The path of the ray of light incident normally on the hypotenuse side is shown in
Sunlight that bounces off a surface is said to be __________ from the surface.
  • Radiated
  • Absorbed
  • Emitted
  • Reflected
If the light moving in a straight line bends by a small but fixed angle, it may be a case of
  • reflection
  • refraction
  • diffraction
  • dispersion
Light propagates $$2\ cm$$ distance in glass of refractive index $$1.5$$ in time $$t_0$$. In the same time $$t_0$$, light propagates a distance of $$2.25\ cm$$ in a medium. The refractive index of the medium is :
  • $$4/3$$
  • $$3/2$$
  • $$8/3$$
  • $$none\ of\ these$$
A convex mirror of focal length $$10cm$$ is shown in figure. A linear object $$AB=5cm$$ is placed along the optical axis. Point $$A$$ is at distance $$25cm$$ from the pole of mirror. The size of image of $$AB$$ is:
1703693_c5247f49d7ee45c9b166ba02317f3664.png
  • $$2.5cm$$
  • $$0.64cm$$
  • $$0.36cm$$
  • None of these
When an object is placed at a distance of $$25 \ cm$$ from a mirror, the magnification is $$m_1$$. But the magnification becomes $$m_2$$, when the object is moved $$15 \ cm$$ farther away with respect to the earlier position. If $$\dfrac{m_1}{m_2}=4$$, then find the focal length of the mirror and what type of mirror it is? 
  • $$20 \ cm$$ , convex
  • $$20 \ cm $$ , concave
  • $$10 \ cm$$ , convex
  • $$10 \ cm $$ , concave
The second lens in this optical instrument can not : 
1760213_d5ba680060fd436a8cd6bb59869c86b2.png
  • Cause the light rays to focus closer than they would with the first lens, acting alone
  • Cause the light rays to focus farther away than they would with the first lens acting alone
  • Cause the light beam to diverge after refraction from it
  • Make the beam parallel
An object of size $$7.5\ cm$$ is placed in front of a convex mirror of radius of curvature $$25\ cm$$ at a distance of $$40\ cm.$$ The size of the image should be
  • $$2.3\ cm$$
  • $$1.7\ cm$$
  • $$1\ cm$$
  • $$0.8\ cm$$
0:0:1


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