Subject

Mathematics

Class

CBSE Class 12

Pre Boards

Practice to excel and get familiar with the paper pattern and the type of questions. Check you answers with answer keys provided.

Sample Papers

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 Multiple Choice QuestionsShort Answer Type

21.

The scalar product of the vector straight a with rightwards arrow on top equals space straight i with hat on top plus straight j with hat on top plus straight k with hat on top with a unit vector along the sum of vectors straight b with rightwards arrow on top equals 2 straight i with hat on top plus 4 straight j with hat on top minus 5 straight k with hat on top space space and space straight c with rightwards arrow on top space equals space straight lambda straight i with hat on top plus 2 straight j with hat on top plus 3 straight k with hat on top is equal to one. Find the value of straight lambda and hence find the unit vector along straight b with rightwards arrow on top plus straight c with rightwards arrow on top.

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22. Evaluate colon
integral subscript 0 superscript straight pi fraction numerator 4 straight x space sinx over denominator 1 plus cos squared straight x end fraction dx
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23.

Evaluate:
integral fraction numerator straight x plus 2 over denominator square root of straight x squared plus 5 straight x plus 6 end root end fraction dx

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24.

An experiment succeeds thrice as often as it fails. Find the probability that in the next five trials, there will be at least 3 successes.

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25. If space straight y space equals space Pe to the power of ax plus Qe to the power of bx show that
straight d to the power of 2 straight y end exponent over dx squared minus left parenthesis straight a plus straight b right parenthesis dy over dx plus aby space equals 0
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26. If space straight x equals cost left parenthesis 3 minus 2 cos squared straight t right parenthesis space and space straight y equals sint left parenthesis 3 minus 2 sin squared straight t right parenthesis comma space find space the space value space of space dy over dx at space straight t equals straight pi over 4.


straight x equals cost space left parenthesis 3 minus 2 cos squared straight t right parenthesis
and
straight y equals sint left parenthesis 3 minus sin squared straight t right parenthesis
We space need space to space find space dy over dx colon
dy over dx equals fraction numerator begin display style dy over dx end style over denominator begin display style dx over dt end style end fraction
Let space us space find space dx over dt colon
straight x equals cost left parenthesis 3 minus 2 cos squared straight t right parenthesis
dx over dt equals cost left parenthesis 4 cost space sint right parenthesis plus left parenthesis 3 minus 2 cos squared straight t right parenthesis left parenthesis negative sint right parenthesis
rightwards double arrow dx over dt equals negative 3 sint plus 4 cos squared tsint plus 2 cos squared tsint
Let space us space find space dy over dt colon
straight y equals sint left parenthesis 3 minus 2 sin squared straight t right parenthesis
dy over dt equals sint left parenthesis negative 4 sint space cost right parenthesis plus left parenthesis 3 minus 2 sin squared straight t right parenthesis space left parenthesis cost right parenthesis
rightwards double arrow dy over dt equals 3 cost minus 4 sin squared tcost minus 2 sin squared tcost
Thus comma space dy over dx equals fraction numerator 3 cost minus 4 sin squared tcost minus 2 sin squared tcost over denominator negative 3 sint plus 4 cos squared tsint plus 2 cos squared tsint end fraction
rightwards double arrow space dy over dx equals fraction numerator 3 cost minus 6 sin squared tcost over denominator negative 3 sint plus 6 cos squared tsint end fraction
rightwards double arrow dy over dx equals fraction numerator 3 cost left parenthesis 1 minus 2 sin squared straight t right parenthesis over denominator negative 3 sint left parenthesis 1 minus 2 cos squared straight t right parenthesis end fraction
rightwards double arrow dy over dx equals fraction numerator 3 cost left parenthesis 1 minus 2 sin squared straight t right parenthesis over denominator 3 sint left parenthesis 2 cos squared straight t minus 1 right parenthesis end fraction
rightwards double arrow dy over dx equals fraction numerator cost space over denominator sint end fraction open square brackets because 2 cos squared straight t minus 1 equals 1 minus 2 sin squared straight t close square brackets
rightwards double arrow dy over dx equals cot space straight t
rightwards double arrow open parentheses dy over dx close parentheses subscript straight t equals straight pi over 4 end subscript equals cot straight pi over 4 equals 1
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27.

Find the particular solution of the differential equation log open parentheses dy over dx close parentheses equals 3 straight x plus 4 straight y comma space given space that space straight y space equals space 0 comma space when space straight x equals space 0.

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28.

Find the value of p, so that the lines:
are perpendicular to each other. Also find the equations of a line passing through a point (3, 2, -4) and parallel to line l1.

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 Multiple Choice QuestionsLong Answer Type

29.

Find the equation of the plane through the line of intersection of the planes x + y + z = 1 and 2x + 3y + 4z = 5 which is perpendicular to the plane x- y + z = 0. Also find the distance of the plane obtained above, from the origin.

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30.

Find the distance of the point (2, 12, 5) from the point of intersection of the line 
straight r with rightwards arrow on top equals 2 straight i with hat on top minus 4 straight j with hat on top plus 2 straight k with hat on top plus straight lambda open parentheses 3 straight i with hat on top plus 4 straight j with hat on top plus 2 straight k with hat on top close parentheses space and space the space plane space straight r with rightwards arrow on top. open parentheses straight i with hat on top minus 2 straight j with hat on top plus straight k with hat on top close parentheses equals 0.

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