Sir C.V.Raman Science Talent Search Competition 2024-25 Std -7th & 8th
Q.1 Write the labels for A, B, C and D.
A-Secondary root
B-Primary root
C-Rot cap
D-Parts of root
Q.2 Write the labels for A, B, C and D.
A-Carbon rod
B-Porus paper lining
C-Manganese dioxide & graphite
D-Ammonium chloride &Zinc chloride
Q.3 Write the labels for A, B, C and D.
A-Magnetic force
B-Electrostatic force
C-Gravitational force
D-Muscular force
Q.4 Write the labels for A, B, C and D.
A-Incisors
B-Canine
C-Premolars
D-Molars
Q.5 Write the labels for A, B, C and D.
A-Earthquake
B-Epicenter
C-Hypocenter
D-Seismic waves
Q.6 Read the following passage and write the answers for questions asked below.
A few years ago, the planets Jupiter, Mars, Venus and constellations Orion, Saptarshi, Pole Star were clearly visible by naked eyes. Nowadays, sky watching programmes are organized at many places, but more than half of the sky seems to be smoky. Light rays from artificial sources like street poles, vehicles, floodlights etc. spread in the sky. Now light pollution has been added to sound pollution.
Light pollution was first sensed by astronomers. Due to dust and extra night light spread upwards from the horizon, the stars are not visible. So, they became restless and started The Dark Sky Movement’ in the 1980s. This movement is about the efforts to reduce the severity of light pollution .
Light pollution started because of industrialisation and the urban settlements, factories following it. Day by day the severity of light pollution is increasing due to floodlights on the buildings and advertisement boards, light coming out from the windows, street lights, special light systems used for cricket-football night matches.
Most of the accidents of small two wheelers occur at night as they can’t judge the roads.
Because of sharp headlights from trucks, the road and vehicles on the opposite side can’t be seen. Many vehicles throw unnecessary amounts of light, this is also an example of light pollution.
If you can’t sleep due to light coming in from the window, it is light pollution for you. This is called ‘Light Trespassing’. We try to reduce the light intensity by putting thick curtains. Additional light has many medical effects. Working in intense light increases blood pressure, stress, fatigue and mental ailments like anxiety. Efficiency of the people working in intense light at nights goes on receding.
In India, no reason is required for artificial light decoration. Diwali, Navaraatri, Ganeshotsaw, personal celebrations etc. Think twice before switching on the light decoration with / without reason, day-night matches played in intense light, stadium cricket, floodlights on big buildings, high capacity electric bulbs and sodium vapor lamps, 4-5 mercury vapor lamps in a square etc. Every time, think “Is it really necessary ? “
Writer – Mohan Madwanna
1) How was the first light pollution sensed ?
Ans. _______________________________________________________________________
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2) Which efforts are made by the movement related to light pollution ?
Ans. _______________________________________________________________________
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3) What are the effects of light pollution on human life ? (Any 2)
Ans. __________________________________________________________________________
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4) What are the reasons for light pollution? (Any 2)
Ans. ________________________________________________________________
5) What measures should be implemented to reduce light pollution? (Any 2)
Ans. ________________________________________________________________
Q.7 Sulphur atom has 6 electrons in its outermost orbit, therefore its valency is
A] 6 . B] 2 C] 1 D] 3
Ans-B
Q.8 …………………. force is active in atomic structure.
A] Gravitational B] Electrical C] Electromagnetic D] Friction
Ans-C
Q.9 ……………. surfaces transmit light, while……………………. surfaces do not.
A] Opaque, transparent B] Transparent, opaque
C] Thick, transparent D] Transparent, thick
Ans-B
Q.10 If a clock is showing 5.15, then its image in a plane mirror will show ;….
A] 5.55 B] 6.15 C] 6.45 D] 7.45
Ans-C
Q.11 If two poles of a magnet are simultaneously brought near a freely hung iron bar, what will happen ?
A] Both times attraction B] Both times repulsion
C] First attraction, then repulsion D] No reaction at all.
Ans-A
Q.12 Magnet is not used in………………..
A] cupboard shutters B] refrigerator C] pin holder D] window shutters
Ans-D
Q.13 Pressure increases with……………. in force and …………………. in area.
A] increase, reduction B] reduction, increase
C] reduction, reduction D] increase, increase
Ans-A
Q.14 Railway air brakes were invented by a scientist……………………..
A] Pascal B] Otto von Guericke C] Archemedes D] George Westinghouse
Ans-D
Q.15 ……………….. is produced in a gobar gas plant.
A] Hydrogen B] Butane C] Isobutane D] Methane
Ans-D
Q.16 Compounds of.……………………………. are found in all fossil fuels.
A] halogen B] hydrocarbons C] metals D] non-metals
Ans-B
Q.17 Continuous flow of electrons is called…………………………..
A] electrostatic potential B] electronic current
C] electric current D] electrical Circuit
Ans-C
Q.18 In an electrical circuit, this sign is used for………
A] ameter B] key
C] voltmeter D] electric cell
Ans-D
Q.19 Everyday the moon rises about ………. than the previous day.
A] 10 minutes earlier B] one hour later
C] 50 minutes later D] two hours earlier
Ans-C
Q.20 The Earth has seasons like summer and winter because
A] the Earth has living world
B] the Earth has gravitational force.
C] the Earth has atmosphere
D] the axis of rotation of the Earth is slightly inclined
Ans-D
Q.21 The method used to separate the ingredients of crude oil is …
A] evaporation B] fractional distillation C] freezing D] sublimation
Ans-B
Q.22 Chemical reaction between black iron and yellow sulphur results in ——– colored ————.
A] yellow, iron oxide Bl white, sulphur oxide
C] black, iron sulphide D] black, iron oxide
Ans-C
Q.23 Sodium metal is kept in kerosene, because……..
Al it burns in the air
B] it reacts with water and gets dissolved
C] it is heavier than kerosene and doesn’t react with it
D] all the above reasons
Ans-D
Q.24 The chemical symbols of potassium and gold are serially…… and……………….
A] P, G B] K, Au C] P, Ag D] K, S
Ans-B
Q.25 Valencies of elements are always ………. numbers.
A] even Bl odd C] composite D]whole
Ans-D
Q.26 Which of the following is NOT a property of a catalyst ?
A] It actually takes part in the reaction B] It does not take part in the reaction
C] It increases the velocity of the reaction D] Its mass does not change
Ans-A
Q.27 Which factor from the following is different with reference to the photosynthesis process
A] Carbon dioxide and sunlight B] Nitrogen
Cl Chlorophyll in the leaves D] water, minerals, salts
Ans-B
Q.28 The…………………… group of atoms is an important constituent of bases.
A]H B] OH C] H2 D] O2
Ans-B
Q.29 Sour fruits like oranges, sweet limes, lemons contain ……. acid.
A] tartaric B] ascorbic C] citric D] buteric
Ans-C
Q.30 Silicon dioxide is used in the production of.…………….
A] plastic B] rubber C] glass and cement D] cloth and paper
Ans-C
Q.31 Silver turns blackish as……………….. from the air reacts with it.
A] oxygen B] carbon dioxide C] sulphur dioxide D] hydrogen sulphide
Ans-D
Q.32 …………………….. is evolved from a fire extinguisher.
A] Carbon dioxide B] Methane C] Oxygen D] Ethane
Ans-A
Q.33 ………………………………………… from the following are noble metals.
A] Copper and zinc B] Silver and aluminum
C] Palladium and rhodium D] Silver and magnesium
Ans- C
Q.34 The stems of desert plants are green because..
A] stems store water.
B] stems store food.
C] desert plants do not have flowers.
D] due to lack of leaves, the stems have to perform photosynthesis.
Ans-D
Q.35 From the following………………………… is NOT a greenhouse gas.
A] nitrous oxide B] xenon C] methane D] CFC
Ans-B
Q.36 Depletion of biodiversity occurs because of……………………………..
A] increasing population B] single crop method
C] deforestation and hunting D] All above
Ans-D
Q.37 ………….. preserve the strains of local varieties.
A] Cooperative agricultural institutes B] Local banks
C] Seed banks D] Seed store
Ans-C
Q.38 To regulate the substances coming in and going out of a cell, is the function of….
A] vacuole B] cell membrane C] cytoplasm D] mitochondria
Ans- B
Q.39 ………………. from soil independently fix the atmospheric nitrogen.
A] Azotobacter B] Rhizobium C] Staphylococcus D] Clostridium
Ans-A
Q.40 …………………….. is grown as an alternative source of fuel.
A] Rose B] Oscimum C] Marigold DJ Ranbhendi
Ans-D
Q.41 Who is different among us?
A] Moong B] Maize C] Bajra D] Jowar
Ans-A
Q.42 Find out the wrong statement from the following.
A] The soil on the land is formed by a natural process.
B] The process of soil formation is fast.
C] Microbes, worms and insects are found in the soil.
D] Land is an important resource.
Ans-B
Q.43 The frog breathes in water as well as under the ground through the skin, while on the ground it breathes with
A] Nose and lungs B] Skin
C] Gills D] Both A and B are correct
Ans-A
Q.44 Aerial roots, stilt roots, runners, breathing roots are of which types of roots?
A] taproots B] fibrous roots C] adventitious roots D] modified roots
Ans-C
Q.45 Which ecosystem is shown in the picture ?
A] Forest B] Desert
C] Grassland D] Iceland
Ans-B
Q.46 Which useful changes are observed after two-three days when soaked moth beans / gram seeds are placed in a moist cotton ball?
A] The part growing from inside the seed towards the soil can be seen.
B] The part that grows above the soil can be seen.
C] Only A
D] Both A & B.
Ans-D
Q.47 In the pasteurization process the milk is heated to a temperature of —– °C for 15 minutes.
A] 80 B] 60 C] 90 D] 70
Ans-D
Q.48 When you go out on holiday, you like to eat different foods. Before eating you think about which of the following?
A] Where they are made and which water is used for the preparation?
B] Where are they kept for selling?
C] Does the person serving the food has clean hands?
D] All of above
Ans-D
Q.49 The school is at a distance of 1200 meters from Anil’s house. It takes him 10 minutes to cover this distance. What is his speed?
A] 1 m/s B] 2.5 m/s C] 2 m/s D] 3 m/s
Ans-C
Q.50 Electrical energy converts oxygen present in air into which gas?
A] Nitrogen B] Ozone C] Carbon dioxide D] Hydrogen
Ans-B
Q.51 What is the action that transmits heat from the Sun to the Earth millions of kilometers away?
A] Convection of heat B] Conduction of heat
C] Radiation of heat D] Transfer of heat
Ans-C
Q.52 “Walking’ is an example of which muscle function?
A] Involuntary muscle B] Voluntary muscle
C] Heart muscles D] soft muscles
Ans-B
Q.53 What does the adjacent picture show ?——–
A] Manmade air pollution
B] Natural air pollution
C] Soil pollution
D] Water pollution
Ans-A
Q.54 How should we fill the blanks to complete a proper food chain ?
A] Eagle – Frog – Grasshopper B] Grasshopper- Eagle- Frog
C] Grasshopper – Frog – Eagle D] Frog – Eagle – Grasshopper
Ans-C
Q.55 Baker’s yeast belongs to the kingdom…………
A] monera B] protista C] plantae D] fungi
Ans-D
Q.56 Infection of swine flu occurs through…………
A] pigs, mosquito B] pigs, humans
C] housefly, mosquito D] mosquito, humans
Ans-B
Q.57 Downs syndrome is an example of…………….
A] acquired disease B] chronic disease C] hereditary disease D] acute disease
Ans-C
Q.58 What will happen if one the team in tug of war suddenly loses the rope………
A] the opposing team will fall to the front due to balanced force.
B] the opposing team will fall to the front due to unbalanced force.
C] the opposing team will fall backward due to unbalanced force.
D] the opposing team will remain stable due to balanced force.
Ans-C
Q.59 A revolving electric fan continues to revolve even after being switched off as an example of
A] Inertia of direction B] Inertia at rest
C] Zero inertia D] Inertia of motion
Ans-D
Q.60 During recycling of elements, which biotic factors play an important role?
A] Producer B] Decomposer
C] Consumer D] Tertiary consumer .
Ans-B
Q.61 How will you dispose of plastic carry bags.water bottles, milk bags in an eco-friendly manner?
A] Will burn it. B] Will throw it in river water.
C] Will recycle it. D] Will bury it underground.
Ans-C
Q.62 Excessive use of chemical fertilizers causes pollution.
A] only soil B] only air C] soil and water D] soil and air
Ans-C
Q.63 Which of the following is not the result of a land sliding?
A] Artificial reservoirs are created. B] A fire erupts.
C] Rivers change their ways. D] The traffic gets disrupted.
Ans-A
Q.64 Identify prokaryotic cells from the following.
A] Plant cell B] Bacteria C] Animal cell D] Amoeba
Ans-B
Q.65 CO2 + H2O → C6H12O6 + O2 Identify the products in this chemical reaction.
A] Oxygen B] Glucose
C] Carbon Dioxide and water D] Glucose and oxygen
Ans-D
Q.66 Identify the factor which is not responsible for the diminishment of ecosystem
A] Tourism B] Transport C] Water conservation D] Large dams
Ans-C
Q.67 1 calorie heat =…………… joules
A] 8.14 B] 0.418 C14.18 D] 41.8
Ans-C
Q.68 Men and women have different voices. Reason……………..
A] The length of the vocal cords in women is less than the length of the vocal cords in
men.
B] The length of the vocal cords in women is more than the length of the vocal cords in
men.
C] In women, the length of the trachea is less than the length of the vocal cords.
D] The length of the vocal cords in women is equal to the length of the vocal cords in
men.
Ans-A
Q.69 Choose the correct statement.
A] In irregular reflection, the reflected rays are parallel.
B] In irregular reflection, the laws of reflection are followed.
C] In irregular reflection, the angle of incidence is equal for parallel incident rays.
D] In irregular reflection, the angles of reflection are equal.
Ans-B
Q.70 The universe is made up of innumerable………
A] Stars B] Galaxies C] Planets D] Satellites
Ans-B
Q.71 A star is stable because………………..
A] The gravitational force is more than the pressure of gases.
B] The pressure of gases is more than the gravitational force.
C] The gravitational force and the nuclear force are balanced.
D] The gravitational force and the pressure of gases is balanced.
Ans-D
Q.72 The constellation seen in the adjacent figure is ……….. i—————–
A] Saptarshi or The Great Bear
B] Sharmishtha or Cassiopeia
C] Mrug or Orion
D] Vrushchik or Scorpio
Ans-A
Q.73 One light year is………………………………
A] 3,00, 000 km B] 9.5 x 1012 km C] 4.2 years D] 365 days
Ans-B
Q.74 ………………… the mass of the sun is made of helium.
A] 72 % B] 2% C] 29% D] 26%
Ans- D
Q.75 Next year Indian Space Research Organization (ISRO) has planned a Gaganyaan expedition. Before sending astronauts, to test the safety of the spacecraft ISRO will send a humanoid robot named
A] Vyommitra B] Shalu C] Indro D] Sahyaji
Ans-A
Q.76 Which district of Maharashtra has a higher amount of forest cover ?
A] Kolhapur B] Raigad C] Gadchiroli D] Nashik
Ans-C
Q.77 In July 2024 Wayanad from Kerala faced a natural disaster……
A] Earthquake B] Cyclone C] Flood D] Landslide
Ans-D
Q.78 World health day is observed on………
A] 5 June B] 7 April C] 1 December D] 20 March
Ans-B
Q.79 Dajipur- Radhanagari sanctuary in Kolhapur district is famous for…..
A] tigers B] antelopes C] bisons D] elephants
Ans-C
Q.80 Pranayam in yoga is a………….. exercise.
A] muscle B] breathing C] bone D] sit ups
Ans-B
Q.81 The number of sparrows in the surroundings is reducing because of…..
A] electromagnetic emissions from cellular phone towers
B] Modern methods of buildings
C] Increasing pollution in cities
D] all the above
Ans-D