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Q.1) Cinematography is based on which principle? ( 1 mark )

(Q.2) Least distance of vision for a normal eye is ( 1 mark )(a) 25 cm(b) 1 m(c) 30m(d) Infinity

(Q.3) In an eye, where is image formed? ( 1 mark )

(Q.4) What is iris? ( 1 mark )

(Q.5) Where is far point located for a normal eye? ( 1 mark )

(Q.6) Cylindrical lenses are used to correct which type of defects of vision? (1 mark )

(Q.7) Hypermetropia is corrected by which type of lens? ( 1 mark)

(Q.8) What is the cause of cataract? ( 1 mark )

(Q.9) What is least distance of distinct vision? ( 1 mark )

(Q.10) What is a simple microscope? ( 1 mark )

(Q.11) In spectrum which colour bends least? ( 1 mark )

(Q.12) Cataract is a condition ( 1 mark )(a) When the crystalline lens becomes milky and cloudy.(b) There is no loss of vision.(c) It cannot be cured.(d) Eye can not identify colours

(Q.13) Which of the following does not describe working of the human eye?( 1 mark )(a) The lens system forms an image on a light sensitive screen called the retina.

(b) Light enters the eye through a thin membrane called the cornea.(c) Rainbow is formed due to splitting of white light.(d) Iris is a dark muscular diaphragm that controls the size of the pupil for regulating the amount of light entering into the eye.

(Q.14) Human eye is one of the most valuable and sensitive organ that ( 1 mark )(a) Enables us to see the wonderful world and colours around us(b) Can not identify the objects(c) Is like a telescope(d) Cannot help us to distinguish things

(Q.15) Iris contracts the pupil ( 1 mark )(a) In bright light

(b) To allow more light to enter(c) In darkness(d) To protect from danger

(Q.16) Electrical signals generated by light sensitive cells of retina are sentto the brain via (1 mark )(a) Motor nerves(b) Optic nerves(c) auditory nerves(d) Spinal cord

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(Q.17) Accommodation of a human eye is the property of ( 1 mark )(a) The eye lens to adjust its focal length(b) The eye to see different colors(c) Filling the eyes with tears(d) Ability to adjust the size of image

(Q.18) The eye lens forms a ___________ and _________ image of the object on theretina. ( 1 mark )(a) Virtual and erect(b) Real and inverted(c) Real and erect(d) Virtual and erect

(Q.19) Light sensitive cells get activated on ( 1 mark )(a) Illumination(b) Seeing the different colors(c) Facing opaque objects(d) Receiving message from the brain

(Q.20) Color blindness is the name given to ( 1 mark )(a) Inability to distinguish between colors(b) Inability to see anything(c) Inability to see in dark

(d) Inability to see in bright light

(Q.21) In eye, light enters through a thin membrane called ( 1 mark )(a) Cornea(b) Retina(c) Pupil(d) Iris

(Q.22) A person is not able to see distant objects clearly, because ( 1 mark )(a) He is suffering from myopia(b) The defect can be rectified by using a convex lens(c) The defect can be rectified by using a convex mirror(d) Focal length of the eye lens is too large

(Q.23) Hypermetropia is also known as far sightedness because ( 1 mark )(a) The person is not able to see clearly the distant objects, but can see nearobjects clearly(b) The person is able to see clearly the distant objects, but not near objects(c) The person is not able to see clearly the distant or near objects(d) The person is able to see clearly the distant or near objects

(Q.24) Presbyopia can be corrected by ( 1 mark )(a) Using bifocal lenses(b) Using concave lenses only.(c) Using binoculars(d) Using sunglasses

(Q.25) The shape of the triangular prism ( 1 mark )(a) Makes the emergent ray bend at angle to the direction of the incident ray(b) Does not causes dispersion of the light.(c) Makes emergent ray ant parallel to the incident ray(d) Direction of emergent ray is free from the shape of prism

(Q.26) Splitting of white light on passage through a triangular prism ( 1 mark )(a) Takes place due to the base of the prism(b) Is known as dispersion of light

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(c) Is a band of six colors known as spectrum(d) Is called interference

(Q.27) Dispersion of white light takes place because _________.Choose the most appropriate option. ( 1 mark )(a) Different colors of light bend through different angles with the incident ray.(b) The red light bends the least and the violet light bends the most.(c) Prism is made up of glass.(d) Refractive index of glass is not uniform in the prism

(Q.28) Placement of another identical prism in an inverted position with respectto the first and allowing the colors of spectrum to pass through it will ( 1 mark )(a) Change the spectrum into white light(b) Change the spectrum into a black band(c) Keep the spectrum as before(d) Split into more colors

(Q.29) Atmospheric refraction occurs because ( 1 mark )(a) Light is traveling through vacuum and air(b) Refractive index of atmosphere keeps changing because its physical conditions do not remain same(c) Light suffers total internal reflection

(d) Light suffers dispersion

(Q.30) Twinkling of a star is due to ( 1 mark )(a) Atmospheric refraction of sunlight(b) Atmospheric refraction of starlight(c) Lightning in the sky(d) Due to total internal reflection

(Q.31) The path of light passing through a clear solution is not visible, but becomes visible through a colloid ( 1 mark )(a) Because light is scattered by relatively larger particles(b) Because light is getting refracted(c) Because light is getting refracted as well reflected

(d) Because light is transmitted

(Q.32) Which one of the following is the correct option? ( 1 mark )(a) Size of scattering particles Dispersion of light(b) Very fine scattering particles Blue light gets scattered(c) Large scattering particles No dispersion or scattering of light(d) Opaque particles Tyndall effect

(Q.33) The sky appears blue because ( 1 mark )(a) Molecules of air and other particles in the atmosphere are bigger than wavelength of visible light.(b) Light of shorter wavelengths at the blue end are scattered more than the redlight whose wavelength is 1.8 times.

(c) The scattered blue light do not enters our eyes.(d) Sky is itself blue in color

(Q.34) Danger signal lights are usually red in color because ( 1 mark )(a) It is a dangerous color(b) It is most scattered by fog or smoke(c) It has larger wavelength and can be seen from a distance(d) Red color is good for eye

(Q.35) Far point of a normal human eye is: ( 1 mark )

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(a) 100 m(b) 500 m(c) 100 Km(d) Infinity

(Q.36) During transplantation of eye, ___ is transplanted. ( 1 mark )(a) Lens(b) Retina(c) Cornea(d) Iris

(Q.37) The diameter of eyeball is approximately: ( 1 mark )(a) 2.0 cm(b) 2.3 cm(c) 2.5 cm(d) 2.7 cm

(Q.38) I in VIBGYOR signifies: ( 1 mark )(a) Indigo(b) Incident ray(c) Image(d) Inverted

(Q.39) What happens to the image distance in the eye when we increase the distan

ce of an object from the eye? ( 2 Marks )

(Q.40) Why does the sky appear dark instead of blue to an astronaut? ( 2 Marks )

(Q.41) Define dispersion and spectrum? ( 2 Marks )

(Q.42) What do you understand by power of accommodation of the eye? ( 2 Marks )

(Q.43) Define least distance of distinct vision. ( 2 Marks )

(Q.44) Why does it take some time to see objects in a dim room when you enter the room from bright sunlight outside? (3Marks )

(Q.45) What is presbyopia? How is it corrected? ( 3 Marks )

Q.46) Why do stars twinkle? ( 3 Marks ) (Q.47) How will you say that white lightof the sun is made of seven colors? ( 3 Marks )

(Q.48) The far point of a myopic person is 80cm in front of the eye. What is thenature and power of the lens required to correct the problem? ( 3 Marks )

(Q.49) What is short sightedness or myopia? What causes myopia? How is myopia corrected? ( 5 Marks )CBSE Class-XSubject Science

Topic- Reflection and Refraction

Q.1) The wavelength of visible light is in the range ( 1 mark )

(a) 4 10-7 m to 8 10-7 m(b) 4 107 m to 8 107 m(c) 4 103 m to 8 103 m(d) 2X 10-3m to 3X 10-4m

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(Q.2) What is the property of image formed by a concave lens?(1mark )

(Q.3) Name the three primary colors? ( 1 mark )

(Q.4) For which color the refractive index of material is maximum? ( 1 mark)

(Q.5) What color we obtain when we mix red and green? ( 1 mark )

(Q.6) What happens to the light when it travels from denser to rarer medium? ( 1mark )

(Q.7) Where will the image be formed when an object is placed between the pole and focus point of the mirror? ( 1 mark )

(Q.8) Can an enlarged image be formed by a convex mirror? ( 1 mark )

(Q.9) Will the focal length of an image change, when it is placed in water? ( 1mark )

(Q.10) Can total internal reflection take place when light travels from rarer todenser medium? ( 1 mark )

(Q.11) A convex lens has a focal length of 50cm.What is its power? ( 1 mark )

(Q.12) An object placed at F of a convex lens will produce an image ( 1 mark )

(a) At F(b) Highly diminished(c) Real and Inverted(d) Virtual

(Q.13) Mirrors used in vehicle headlights are: ( 1 mark )

(a) Concave mirrors(b) Convex mirrors(c) Plane mirrors(d) Any spherical mirror

(Q.14) Dispersion of light by a glass prism takes place because of ( 1 mark )

(a) Difference in time period of the constituents of light.(b) Difference in speeds of various constituents of white light.(c) Scattering of light by the surface of the glass prism.(d) Due to total internal reflection

(Q.15) Negative value of focal length of a spherical mirror indicates that it is( 1 mark )

(a) Concave mirror(b) Convex mirror

(c) Plane mirror(d) Convex mirror of small focal length

(Q.16) Light is a form of ___________ radiation ( 1 mark )

(a) Electrical(b) Mechanical(c) Longitudinal(d) Electromagnetic

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(Q.17) A ________ image can be obtained on a screen. ( 1 mark )

(a) Real(b) Virtual(c) Erect(d) Inverted

(Q.18) Refraction of light can take place at the boundary of ( 1 mark )

(a) Transparent media(b) Opaque media(c) Any medium(d) Rarer medium

(Q.19) According to the laws of reflection ( 1 mark )

(a) Angle i = Angle r(b) Sine i = sine r(c) Sine i / Sine r = constant(d) tan i = tan r

(Q.20) An object placed at F of a concave mirror will produce an image ( 1 mark)

(a) At focus(b) Diminished(c) Real and Inverted(d) Virtual

(Q.21) An object placed at infinity of a concave mirror will produce an image (1mark )

(a) Behind the mirror(b) Diminished(c) Virtual and erect(d) Enlarge

(Q.22) An object placed at F of a concave lens will produce an image ( 1 mark )

(a) On opposite side of the object(b) Enlarge(c) Virtual and erect(d) Real and inverted

(Q.23) An object placed at 2F of a convex lens will produce an image ( 1 mark )

(a) At 2F(b) Enlarge(c) Real and Inverted(d) Virtual

(Q.24) An object placed between F and 2F of a convex lens will produce an image( 1 mark )

(a) Virtual(b) Diminished(c) Real and Inverted(d) Erect

(Q.25) According to the laws of refraction (Snells law) ( 1 mark )

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(a) Angle i = Angle r(b) Sine i = sine r(c) Sine i / Sine r = constant(d) tan i= tan r

(Q.26) Absolute Refractive index of a substance is ( 1 mark )

(a) Speed of light in vacuum / Speed of light in the medium(b) Speed of light in water / Speed of light in the medium(c) Speed of light in the medium / Speed of light in air(d) Speed of light in medium/speed of light in wet

(Q.27) According to Cartesian Sign Convention ( 1 mark )

(a) Object distance is always negative(b) Object distance is always positive(c) Image distance is always negative(d) Image distance is always positive

(Q.28) Magnification produced by a concave mirror is ( 1 mark )

(a) Negative for a real image and Positive for a virtual image(b) Only positive

(c) It produces no magnification(d) Only negative

(Q.29) A ray of light propagates from an optically denser medium to an opticallyrarer medium. ( 1 mark )

(a) It will bend towards the normal after refraction.(b) It will bend away from the normal after refraction.(c) It will continue to go on the same path after refraction.(d) It will refract making an angle of refraction equal to the angle of incidence.

(Q.30) Radius of curvature of a spherical mirror (or lens) is ( 1 mark )

(a) Half of its focal length(b) Double of its focal length(c) Equal to its focal length(d) There is no relation

(Q.31) The distance between a spherical lens and the image is 15 cm. The lens is( 1 mark )

(a) Concave lens(b) Convex lens(c) Either of the two irrespective of the object distance(d) Either Concave lens or Convex lens with object between O and F

(Q.32) Power of a lens is ( 1 mark )

(a) Equal to its focal length(b) Reciprocal of the focal length (in meters)(c) Square of its focal length(d) Reciprocal of its radius of curvature

(Q.33) Lens formula is expressed as ( 1 mark )

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(Q.43) Why do we prefer a convex mirror as a rear-view mirror in vehicles ( 2 Marks )

(Q.44) Define reflection of light. ( 2 Marks )

(Q.45) Find the power of a concave lens of focal length 2m. ( 2 Marks )

(Q.46) Find the focal length of a convex mirror where radius of curvature is 32cm. ( 2 Marks )

(Q.47) What are the uses of a concave mirror? ( 3 Marks )

(Q.48) What is the difference between real and virtual images? ( 3 Marks )

(Q.49) A doctor has prescribed a corrective lens of power + 1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging? ( 3 Marks)

(Q.50) What is refraction of light? Write a law of refraction. ( 3 Marks )

(Q.51) Light enters from air to glass having refraction index 1.50. What is thespeed of light in the glass? The speed of light in vacuum is 3108 ms-1. ( 3 Marks)

(Q.52) An object is placed at a distance of 10cm from a convex mirror of focal length 15 cm. Find the position and nature of the image.( 5 Marks )

(Q.53) An object 5 cm in length is held 25 cm away from a converging lens of focal length 10cm. Draw the ray diagram and find the position, size and nature of the image formed. ( 5 Marks )

(Q.54) An object is placed at 10cm in front of a concave mirror of focal length15cm. Find the position, nature and size of the image.

(Q.1) In thermal power plant, heat energy is converted into ( 1 mark )(a) Light energy

(b) Electrical energy(c) Sound energy(d) Potential energy

(Q.2) Storage of water in reservoirs for hydro power plants cause socio-economicproblems besides ( 1 mark )(a) Air pollution.(b) Destruction of large eco systems.(c) Water pollution.(d) Sound pollution

(Q.3) Hydro Power Plants utilize the potential energy of water stored at a height by ( 1 mark )

(a) Changing potential energy to kinetic energy of flowing (falling) water and then converting it to electrical energy.(b) Changing potential energy to heat energy of water and then converting it toelectrical energy.(c) Changing potential energy to gravitational energy of water and then converting it to electrical energy.(d) There is no interchange of energy takes place

(Q.4) Oxides of Carbon, Nitrogen and Sulphur released on burning of fossils fuels are harmful because ( 1 mark )

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(a) They are acidic oxides and can cause acid rains.(b) They cause noise pollution(c) They cause sound problem(d) They cause vision disorder.

(Q.5) Which of the following is a green house gas?( 1 mark )(a) Oxygen(b) Nitrogen(c) Ozone(d) Methane

(Q.6) Minimum wind speed required for moving turbines is: ( 1 mark )(a) >24 Km/h(b) >15 Km/h(c) >12 Km/h(d) >9 Km/h

(Q.7) Power plants based on geothermal energy are found in: ( 1 mark )(a) South Africa(b) New Zealand(c) Zimbabwe(d) Denmark

(Q.8) Wood, coal, energy of flowing water and wind are considered to be: ( 1 mar

k )(a) Conventional sources of energy(b) Unconventional sources of energy(c) Renewable sources of energy(d) Non-renewable sources of energy

(Q.9) Kinetic energy of moving air or winds in coastal or hilly areas is harnessed to do mechanical work or generate electricity by using: ( 1 mark )(a) Wind Mills(b) Generators(c) Electric Motors(d) Shafts

(Q.10) Which of the following is not correct about the construction of solar cookers or solar heaters ( 1 mark )(a) Black surface absorb more heat as compared to white objects.(b) Spherical reflecting surfaces can be utilized to concentrate solar energy.(c) Covering with a glass plate cause increase in temperature by green house effect.(d) Black surface do not absorb any heat.

(Q.11) The material which is used in making solar cell is ( 1 mark )(a) Aluminum(b) Carbon(c) Silicon(d) Iron

(Q.12) Ocean-Thermal-energy conversion plants operate if ( 1 mark )(a) Water on the surface of oceans is cold.(b) Temperature difference between the water at surface and water at depths up to 2 km is at least 293 K or 20o C.(c) Temperature difference between the water at surface and water at depths up to 2 km is around 100C(d) It is independent of temperature difference between the water at surface andwater at depths.

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(Q.13) Which of the following is not a form of energy: ( 1 mark )(a) Mechanical energy(b) Heat Energy(c) Muscular Energy(d) Frictional energy.

(Q.14) Pollution caused by burning of fossil fuels can be controlled to some extent ( 1 mark )(a) By increasing the efficiency of the combustion process.(b) By using fans in the vehicles.(c) By increasing their cost.(d) Banning the use of fossils fuels.

(Q.15) Fossil fuels are considered to be non-renewable sources of energy because( 1 mark )(a) They are produced underground and become costly to extract.(b) They take millions of years to be produced though used in a little time.(c) They produce a lot of smoke.(d) They are less efficient fuels.

(Q.16) Global demand for energy has grown to tremendous levels because of ( 1 mark )(a) Increasing industrialization(b) Zest for better quality of life.

(c) Transport(d) all round development

(Q.17) It is a well known fact that energy can neither be created nor be destroyed, but still we say that there is an energy crisis because ( 1 mark )(a) Forms of energy keep changing(b) Total energy before and after remains constant, but some of it is used to carry other functions.(c) Usable form of energy is dissipated to the surroundings in less usable forms.(d) We do not know how to use energy

(Q.18) What is non-renewable source of energy? ( 1 mark )

(Q.19) Which type of energy we use to perform our day to day work? ( 1 mark )

(Q.20) Can you place alcohol under the category of renewable source of energy? (1 mark )

(Q.21) Name a renewable source of energy that we can harness for the whole yearnon-stop?? ( 1 mark )

(Q.22) Which component of sunlight is responsible for carrying heat? ( 1 mark )

(Q.23) Which material is used for making solar cell? ( 1 mark )

(Q.24) Name two renewable sources of energy? ( 1 mark )

(Q.25) Name two non-renewable sources of energy? ( 1 mark )

(Q.26) What is tidal energy? ( 1 mark )

(Q.27) Which type of biogas plant has longer life? ( 1 mark )

(Q.28) Pick out the incorrect statement regarding a good source of energy ( 1 mark )

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(a) Would do large amount of work per unit volume or mass.(b) Is accessible and economical.(c) Is easy to store and transport.(d) Is one which is expensive

(Q.29) Burning of fossil fuel gives lot of energy, but has disadvantages in theshape of ( 1 mark )(a) Scarcity of fossil fuels(b) Decreased pollution levels(c) Fossil fuels have less efficiency(d) Fossil fuels can not be used to generate electricity

(Q.30) Improvement in the technology for using conventional sources of energy isbecoming popular. Pick the odd one statement ( 1 mark )(a) More of energy is being extracted in the usable form.(b) Pollution is being restricted.(c) Sewage is also getting disposed.(d) The process involves a lot of wastages

(Q.31) Which of the following is not produced by destructive distillation of wood ( 1 mark )(a) Charcoal that burns without flames and is smokeless.(b) Volatile substances that can be used for manufacture of other products.(c) Harmless water

(d) Acid rain

(Q.32) Biogas plants are gaining popularity in Indian villages because ( 1 mark)(a) They are available free of cost(b) Provide a clean and cheap method of disposing animal and agricultural waste.(c) It is outdated technology so available in villages only(d) It is being encouraged by the government.

(Q.33) An enormous amount of energy is being received by the Earth from __________ for 5 billion years and will continue to do so for another 5 billion years. (1 mark )(a) Oceans

(b) Sun(c) Earths atmosphere(d) Melting snow

(Q.34) A typical solar cell develops ( 1 mark )(a) A potential difference of 0.5 1 V and 0.7 W of electricity.(b) A potential difference of 0.7 V and 0.5 W of electricity.(c) A potential difference of 0.7 V and 1.0 W of electricity.(d) A potential difference of 0.9 V and 2.0 W of electricity.

(Q.35) The nucleus of a heavy atom such as uranium, plutonium or thorium when bombarded with low-energy neutrons, can be split into lighter nuclei and a tremendous amount of energy in: ( 1 mark )

(a) Nuclear Fission(b) Nuclear Fusion(c) Nuclear warfare(d) Biotechnological processes

(Q.36) Many of the sources of energy ultimately extract their energy from: ( 1 mark )(a) The Earth(b) The Sun(c) The Environment

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(d) The Plants

(Q.37) What share of energy requirement in India is met by hydro power plants? (1 mark )(a) Half(b) One-third(c) Quarter(d) Two-third

(Q.38) Tehri dam is constructed over river: ( 1 mark )(a) Narmada(b) Yamuna(c) Ganga(d) Mahanadi

(Q.39) Which of the following is not a clean source of energy? ( 1 mark )(a) Wind(b) Sun(c) Uranium(d) Geothermal energy

(Q.40) What is the % of methane in biogas? ( 1 mark )(a) 75%(b) 80%

(c) 85%(d) 90%

(Q.41) Joining of lighter nuclei to make a heavier nucleus, most commonly hydrogen isotopes to helium such as 2H + 2H ( 1 mark )(a) Nuclear Fusion, which is also the source of energy in the Sun and other stars.(b) Nuclear Fission(c) Isotopes(d) Isobars

(Q.42) What is geothermal energy? When is it available? ( 2 Marks )

(Q.43) Give two merits of solar energy. ( 2 Marks )

(Q.44) What are the limitations of wind energy? ( 2 Marks )

(Q.45) Why the use of dry wood is not considered as good domestic fuel?? ( 2 Marks )

(Q.46) What are the advantages of nuclear energy. ( 3 Marks )

(Q.47) Distinguish between renewable and non-renewable sources of energy. Give examples too. ( 3 Marks )

(Q.48) What are the forms of ocean energy that can be harnessed? Give some place

s in our country where it can be harnessed? ( 3 Marks )

(Q.49) State three advantages of solar cooker? ( 3 Marks )

(Q.50) From one fission of uranium 4x10-11 J of energy is produced. Calculate the total number of fissions necessary per second to generate a power of 20 KW. (3 Marks )

(Q.51) How much energy is gained by an electron when 1 atomic mass is convertedinto energy? Give your answer in MeV. ( 3 Marks )

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(Q.52) What is solar cooker? Explain its working with the help of a neat & labeled diagram. ( 5 Marks )