CBSE%20Class%2010%2C%2012%20date-sheet%20announced%3A%20Go%20through%20this%202021%20CBSE%20Class%2010%20Science%20sample%20paper%20

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%28i%29%20There%20are%20total%2036%20questions%20divided%20into%20four%20sections%20A%2C%20B%2C%20C%20and%20D.

%28ii%29%20Section%20-%20A%3A%20Question%20no.%201%20to%2020%20-%20All%20questions%20and%20parts%20thereof%20are%20of%20one%20mark%20each.%20These%20questions%20contain%20multiple%20choice%20questions%20%28MCQs%29%2C%20very%20short%20answer%20questions%20and%20assertion%20-%20reason%20type%20questions.

%28iii%29%20Section%20-%20B%3A%20Question%20no.%2021%20to%2026%20are%20short%20answer%20type%20questions%2C%20carrying%202%20marks%20each.

%28iv%29%20Section%20-%20C%3A%20Question%20no.%2027%20to%2033%20are%20short%20answer%20type%20questions%2C%20carrying%203%20marks%20each.

%28v%29%20Section%20-%20D%3A%20Question%20no.%2034%20to%2036%20are%20long%20answer%20type%20questions%20carrying%205%20marks%20each.

Note%3A%20There%20is%20no%20overall%20choice.%20However%2C%20internal%20choices%20have%20been%20provided%20in%20some%20questions.

%3Cstrong%3ESECTION%20A%3C/strong%3E

1.%20List%20any%20two%20observations%20when%20Ferrous%20Sulphate%20is%20heated%20in%20a%20dry%20test%20tube%3F

OR

Identify%20the%20products%20formed%20when%201%20mL%20of%20dil.%20Hydrochloric%20acid%20is%20added%20to%201g%20of%20Sodium%20metal%3F

2.%20Write%20the%20chemical%20name%20and%20chemical%20formula%20of%20the%20salt%20used%20to%20remove%20permanent%20hardness%20of%20water.

3.%20Which%20of%20the%20following%20is%20not%20observed%20in%20a%20homologous%20series%3F%20Give%20reason%20for%20your%20choice.

a%29%20Change%20in%20chemical%20properties

b%29%20Difference%20in%20-CH2%20and%2014u%20molecular%20mass

c%29%20Gradation%20in%20physical%20properties

d%29%20Same%20functional%20group

4.%20Why%20does%20the%20Sun%20appear%20white%20at%20noon%3F

5.%20Both%20a%20spherical%20mirror%20and%20a%20thin%20spherical%20lens%20have%20a%20focal%20length%20of%20%28-%2915%20cm.%20What%20type%20of%20mirror%20and%20lens%20are%20these%3F

6.%20The%20image%20formed%20by%20a%20concave%20mirror%20is%20observed%20to%20be%20real%2C%20inverted%20and%20larger%20than%20the%20object.%20Where%20is%20the%20object%20placed%3F

OR

Name%20the%20part%20of%20a%20lens%20through%20which%20a%20ray%20of%20light%20passes%20without%20suffering%20any%20deviation.

7.%20In%20the%20arrangement%20shown%20in%20figure%20there%20are%20two%20coils%20wound%20on%20a%20non-conducting%20cylindrical%20rod.%20Initially%20the%20key%20is%20not%20inserted%20in%20the%20circuit.%20Later%20the%20key%20is%20inserted%20and%20then%20removed%20shortly%20after.

What%20are%20the%20two%20observations%20that%20can%20be%20noted%20from%20the%20galvanometer%20reading%3F

8.%20Draw%20the%20magnetic%20field%20lines%20around%20a%20straight%20current%20carrying%20conductor.

9.%20Two%20unequal%20resistances%20are%20connected%20in%20parallel.%20If%20you%20are%20not%20provided%20with%20any%20other%20parameters%20%28eg.%20numerical%20values%20of%20I%20and%20R%29%2C%20what%20can%20be%20said%20about%20the%20voltage%20drop%20across%20the%20two%20resistors%3F

OR

Some%20work%20is%20done%20to%20move%20a%20charge%20Q%20from%20infinity%20to%20a%20point%20A%20in%20space.%20The%20potential%20of%20the%20point%20A%20is%20given%20as%20V.%20What%20is%20the%20work%20done%20to%20move%20this%20charge%20from%20infinity%20in%20terms%20of%20Q%20and%20V%3F

10.%20Veins%20are%20thin%20walled%20and%20have%20valves.%20Justify.

11.%20How%20is%20the%20wall%20of%20small%20intestine%20adapted%20for%20performing%20the%20function%20of%20absorption%20of%20food%3F

OR

Out%20of%20a%20goat%20and%20a%20tiger%2C%20which%20one%20will%20have%20a%20longer%20small%20intestine%3F%20Justify%20your%20answer.

12.%20Explain%20how%20ozone%20being%20a%20deadly%20poison%20can%20still%20perform%20an%20essential%20function%20for%20our%20environment.%20OR%20Give%20reason%20why%20a%20food%20chain%20cannot%20have%20more%20than%20four%20trophic%20levels.

13.%20State%20the%20role%20of%20pancreas%20in%20digestion%20of%20food.

%3Cstrong%3EFor%20question%20numbers%2014%2C%2015%20and%2016%2C%20two%20statements%20are%20given-%20one%20labeled%20Assertion%20%28A%29%20and%20the%20other%20labeled%20Reason%20%28R%29.%20Select%20the%20correct%20answer%20to%20these%20questions%20from%20the%20codes%20%28a%29%2C%20%28b%29%2C%20%28c%29%20and%20%28d%29%20as%20given%20below%3A%3C/strong%3E

%3Cstrong%3Ea%29%20Both%20A%20and%20R%20are%20true%2C%20and%20R%20is%20correct%20explanation%20of%20the%20assertion.%3C/strong%3E

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%3Cstrong%3Ec%29%20A%20is%20true%2C%20but%20R%20is%20false.%3C/strong%3E

%3Cstrong%3Ed%29%20A%20is%20false%2C%20but%20R%20is%20true.%3C/strong%3E

14.%20Assertion%3A%20After%20white%20washing%20the%20walls%2C%20a%20shiny%20white%20finish%20on%20walls%20is%20obtained%20after%20two%20to%20three%20days.

Reason%3A%20Calcium%20Oxide%20reacts%20with%20Carbon%20dioxide%20to%20form%20Calcium%20Hydrogen%20Carbonate%20which%20gives%20shiny%20white%20finish.

15.%20Assertion%3A%20Food%20chain%20is%20responsible%20for%20the%20entry%20of%20harmful%20chemicals%20in%20our%20bodies.

Reason%3A%20The%20length%20and%20complexity%20of%20food%20chains%20vary%20greatly.

OR

Assertion%3A%20Greater%20number%20of%20individuals%20are%20present%20in%20lower%20trophic%20levels.

Reason%3A%20The%20flow%20of%20energy%20is%20unidirectional.

16.%20Assertion%3A%20A%20geneticist%20crossed%20a%20pea%20plant%20having%20violet%20flowers%20with%20a%20pea%20plant%20with%20white%20flowers%2C%20he%20got%20all%20violet%20flowers%20in%20first%20generation.

Reason%3A%20White%20colour%20gene%20is%20not%20passed%20on%20to%20next%20generation.

%3Cstrong%3EAnswer%20Q.%20No%2017%20-%2020%20contain%20five%20sub-parts%20each.%20You%20are%20expected%20to%20answer%20any%20four%20subparts%20in%20these%20questions.%26nbsp%3B%3C/strong%3E

%3Cstrong%3E17.%26nbsp%3B%3C/strong%3ERead%20the%20following%20and%20answer%20any%20four%20questions%20from%2017%20%28i%29%20to%2017%20%28v%29.

All%20living%20cells%20require%20energy%20for%20various%20activities.%20This%20energy%20is%20available%20by%20the%20breakdown%20of%20simple%20carbohydrates%20either%20using%20oxygen%20or%20without%20using%20oxygen.

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a%29%20Breathing

b%29%20Tissue%20respiration

c%29%20Organ%20respiration

d%29%20Digestion%20of%20food

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Lactic%20acid%20production%20has%20occurred%20in%20the%20athlete%20while%20running%20in%20the%20400%20m%20race.%20Which%20of%20the%20following%20processes%20explains%20this%20event%3F

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Choose%20the%20correct%20combination%20of%20plots%20and%20justification%20provided%20in%20the%20following%20table.

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a%29%20i%29%20%2Cii%29%20only

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%28v%29%20Study%20the%20table%20below%20and%20select%20the%20row%20that%20has%20the%20incorrect%20information.

18.%20Read%20the%20following%20and%20answer%20any%20four%20questions%20from%2018%20%28i%29%20to%2018%20%28v%29.

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%3Cstrong%3ENon-Metallic%20Character%3C/strong%3E

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18%20%28i%29%20Which%20of%20the%20following%20correctly%20represents%20the%20decreasing%20order%20of%20metallic%20character%20of%20Alkali%20metals%20plotted%20in%20the%20graph%3F

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18%20%28iii%29%20Which%20of%20the%20following%20has%20highest%20electronegativity%3F

a%29%20F

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%26nbsp%3B

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