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


Given that

straight y equals Pe to the power of ax plus Qe to the power of bx
Differentiating space the space above space function space with space respect space to space straight x comma
dy over dx equals Pae to the power of ax plus Qbe to the power of bx
Differentiating space once space again comma space we space have comma
fraction numerator straight d squared straight y over denominator dx squared end fraction equals space Pa squared straight e to the power of ax plus Qb squared straight e to the power of bx
Let us now find left parenthesis straight a plus straight b right parenthesis dy over dx colon

left parenthesis straight a plus straight b right parenthesis dy over dx equals left parenthesis straight a plus straight b right parenthesis open parentheses Pae to the power of ax plus Qbe to the power of bx close parentheses space
space rightwards double arrow space left parenthesis straight a plus straight b right parenthesis dy over dx equals Pa squared straight e to the power of ax plus Qabe to the power of bx plus Pabe to the power of bx plus Qb squared straight e to the power of bx
rightwards double arrow space left parenthesis straight a plus straight b right parenthesis dy over dx equals Pa squared straight e to the power of ax plus left parenthesis straight P plus straight Q right parenthesis abe to the power of bx plus Qb squared straight e to the power of bx space space space
Also we have,

aby space equals ab open parentheses Pe to the power of ax plus Qe to the power of bx close parentheses space equals space ab
Thus comma space fraction numerator straight d squared straight y over denominator dx squared end fraction minus left parenthesis straight a plus straight b right parenthesis dy over dx plus aby
equals Pa squared straight e to the power of ax plus Qb squared straight e to the power of bx minus Pa squared straight e to the power of ax minus left parenthesis straight P plus straight Q right parenthesis abe to the power of bx minus Qb squared straight e to the power of bx plus abPe to the power of ax plus abQe to the power of bx
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.
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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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