Question : Coin placed in a bowl when seen from a place just disappears. When water is poured into the bowl without disturbing the coin , the coin
(a) Will not be seen
(c) Becomes visible again
(b) Appears above the water surface
(d) Appears very much deep inside the water
Answer : C
Question : Nature of the image formed by a convex mirror is
(a) Real, inverted, diminished
(c) Real , inverted , enlarged
(b) Virtual, erect, diminished
(d) Virtual, erect, enlarged
Answer : B
Question : The property of a mirror used in burning a paper is
(a) Rays from an object placed at a large distance in a concave mirror after reflection forms the image at the Focus
(b) Rays from an object placed at a large distance in a convex mirror after reflection forms the image at the Focus
(c) Rays from an object placed at Focus after reflection in a concave mirror forms the image at a very large distance.
(d) Rays from an object placed between F and 2F in a concave mirror after reflection forms the image beyond the Focus
Answer : A
Question : The focal length of a concave mirror is 10cm. The position of the object that is useful for getting an enlarged image which can be caught on a screen is
(a) Placed at a distance of 5 cm. from the pole of the mirror
(b) Placed at a distance of 15 cm from the pole of the mirror
(c) Placed at a distance of 35 cm from the pole of the mirror
(d) Placed at a distance of 5 cmfrom the pole of the mirror
Answer : C
Question : The power of a lens is -3.5D. The lens is
(a) Convex
(c) concave
(b) Plano-convex
(d) Plano-concave
Answer : C
Question : Formula to find the refractive index of a medium is
(a) n=speed of light in the medium /speed of light in air
(b) n=1 /speed of light in air
(c) n=speed of light in the air/speed of light in the medium
(d) n=1 /speed of light in the medium
Answer : C
Question : In case of refraction through a glass slab
(a) Incident ray is parallel to the refracted ray
(c) Angle of incidence is equal to the angle of refraction
(b) Incident ray is parallel to the emergent ray
(d) Angle of refraction is equal to the angle of emergence
Answer : B
Question : Mirror that can be chosen to view a tall building in a small mirror is
(a) Plane mirror (c) Convex mirror
(b) Concave mirror (d) Plano-Convex mirror
Question : Mirror formula is
(a) 1/v-1/u =1/f
(c) 1/v+1/u =1/f
(b) M=v/u
(d) M=h/h’
Answer : C
Question : The mirror used by ENT specialists is
(a) Plane mirror
(b) Concave mirror
(c) Convex mirror
(d) Plano-convex mirror
Answer : B
Question : A student obtained a blurred image of an illuminated distant tower on a screen by using a convex lens In order to obtain sharp image of the tower on the screen ,he must shift the lens
(a) towards the screen
(b) away from the screen
(c) away from the lens
(d) either towards away or near the screen
Answer : B
Question : An object AB is placed in front of a convex Lens at its principal focus The image will be formed at
(a) focus
(b) beyond C
(c) Between F & C
(d) infinity
Answer : D
Question : When an object moves closer to a concave lens, the Image formed by it shifts
(a) Away from the lens
(b) Towards the lens
(c) First away and then towards the lens
(d) First towards and then away from the lens
Answer : A
Question : When a ray of light passes from a denser medium to a rarer medium which angle is greater
(a) angle of incidence
(b) angle of refraction
(c) both
(d) none
Answer : B
Question : If optical density of a medium is high then the speed of light in that medium is :
(a) high
(b) low
(c) unchanged
(d) none of these
Answer : B
Question : In convex lens, if the object is at infinity then position of image is at :
(a) Infinity
(b) Between F and 2F
(c) At the Focus
(d) None of these
Answer : C
Question : A light is said to be convergent when :
(a) All the rays spread around from a point source of light
(b) It travels in an irregular pattern
(c) All the rays travel parallel to each other
(d) all the rays converge together to a single point
Answer : D
Question :When the ray of light falls obliquely on the interface of two media and goes to the another medium. It is called:
(a) Reflection of light
(b) Refraction of light
(c) Dispersion of light
(d) Both (a) and (b)
Answer : B
Question :Convex lens is used in case of :
(a) myopia
(b) hypermetropia
(c) presbyopia
(d) astigmatism
Answer : B
Question : Short sightedness is also called as :
(a) myopia
(b) hypermetropia
(c) presbyopia
(d) astigmatism
Answer : A
Question : Cylindrical lens is used in case of :
(a) myopia
(b) hypermetropia
(c) presbyopia
(d) astigmatism
Answer : D
Question : Even in absolutely clear water, a diver cannot see very clearly :
(a) Because rays of light get diffused
(b) Because velocity of light is reduced in water
(c) Because a ray of light passing through the water makes it turbid
(d) Because the focal length of the eye lens in water gets changed and the image is no longer focused sharply on the retina
Answer : D
Question : The persistence of vision of the eye is :
(a) 1 /16 second
(b) 1/5 second
(c) 1/26 second
(d) 1/100 second
Answer : A
Question : In eye, the focusing is done by :
(a) to and fro movement of the eye lens
(b) to and fro movement of retina
(c) change in the convexity of the lens
(d) change in refractive index of the eye fluid
Answer : C
Question : While looking at nearby objects, the muscle __________ so as to ___________ the focal length of eye lens.
(a) Contracts, increase
(b) Relax, increase
(c) Contracts, decrease
(d) Relax, decrease
Answer : C
Question : Which of the following factors is responsible for the refraction :
(a) Optical density
(b) Frequency of light
(c) Angle of incidence
(d) Mass density
Answer : A
Question : Refractive index of a medium does not depends on :
(a) Nature of the medium
(b) Wavelength of the light used
(c) Temperature
(d) Angle of incidence
Answer : C
Question : A far sighted person cannot focus distinctly objects closer than 120 cm. The lens that will permit him to read from a distance of 40 cm will have a focal length :
(a) + 30 cm
(b) – 30 cm
(c) + 60 cm
(d) – 60 cm
Answer : C
Question : The image is always erect in :
(a) Plane mirror
(b) Concave mirror
(c) Convex mirror
(d) Both (a) and (c) are correct
Answer : D
Question : Light waves are similar in nature to :
(a) Gamma rays
(b) x-rays
(c) Cathode rays
(d) Both (a) & (b)
Answer : D
Question : An object of size 2.0 cm is placed perpendicular to the principal axis of a concave mirror. The distance of the object from the mirror equals the radius of curvature. The size of the image will be :
(a) 0.5 cm
(b) 1.0 cm
(c) 1.5 cm
(d) 2.0 cm
Answer : D
Question : An object is placed 20 cm from a convex mirror. Its image is formed 12 cm from the mirror. Find the focal length of the mirror :
(a) 25 cm
(b) 30 cm
(c) 15 cm
(d) 60 cm
Answer : B
Question : A dentist uses a small mirror that gives a magnification of 4 when it is held 0.60 cm from a tooth. The radius of curvature of the mirror is :
(a) 1.60 cm (convex)
(b) 0.8 cm (concave)
(c) 1.60 cm (concave)
(d) 0.8 cm (convex)
Answer : B
Question : A 2.0 cm high object is placed perpendicular to the principal axis of a concave mirror. The distance of the object from the mirror is 30 cm and its image is formed 60 cm from the mirror, on the same side of the mirror as the object. Find the height of the image formed :
(a) 4 cm
(b) 2 cm
(c) 3 cm
(d) 5 cm
Answer : A
Question : When light travels from one medium to the other of which the refractive index is different, then the quantities which will change :
(a) Frequency, wavelength and velocity
(b) Frequency and wavelength
(c) Frequency and velocity
(d) Wavelength and velocity
Answer : D
Question : Ray nature is confirmed by the phenomenon of :
(a) reflection
(b) refraction
(c) both A and B
(d) none of these
Answer : C
Question : Electromagnetic wave theory was proposed by :
(a) Maxwell
(b) Hertz
(c) Huygens
(d) Newton
Answer : A