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.
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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.


The equation of line L1:
fraction numerator 1 minus straight x over denominator 3 end fraction equals fraction numerator 7 straight y minus 14 over denominator straight p end fraction equals fraction numerator straight z minus 3 over denominator 2 end fraction
rightwards double arrow space fraction numerator straight x minus 1 over denominator negative 3 end fraction space equals fraction numerator straight y minus 2 over denominator begin display style straight p over 7 end style end fraction space equals fraction numerator straight z minus 3 over denominator 2 end fraction space space... left parenthesis 1 right parenthesis
The space equation space of space line space straight L subscript 2 colon
fraction numerator 7 minus 7 straight x over denominator 3 straight p end fraction equals fraction numerator straight y minus 5 over denominator 1 end fraction equals fraction numerator 6 minus straight z over denominator 5 end fraction
rightwards double arrow fraction numerator straight x minus 1 over denominator begin display style fraction numerator negative 3 straight p over denominator 7 end fraction end style end fraction equals fraction numerator straight y minus 5 over denominator 1 end fraction equals fraction numerator straight z minus 6 over denominator negative 5 end fraction... left parenthesis 2 right parenthesis

 Since space line space straight L subscript 1 space and space straight L subscript 2 space are space perpendicular space to space each space other comma space we space have
minus 3 cross times open parentheses fraction numerator negative 3 straight p over denominator 7 end fraction close parentheses plus straight p over 7 cross times 1 cross times 2 cross times left parenthesis negative 5 right parenthesis space equals space 0
rightwards double arrow fraction numerator 9 straight p over denominator 7 end fraction plus straight p over 7 equals 10
rightwards double arrow 10 straight p space equals 70
rightwards double arrow straight p equals space 7
Thus space equations space of space lines space straight L subscript 1 space and space straight L subscript 2 space are colon
fraction numerator straight x minus 1 over denominator negative 3 end fraction equals fraction numerator straight y minus 2 over denominator 1 end fraction equals fraction numerator straight z minus 3 over denominator 2 end fraction
fraction numerator straight x minus 1 over denominator negative 3 end fraction equals fraction numerator straight y minus 5 over denominator 1 end fraction equals fraction numerator straight z minus 6 over denominator negative 5 end fraction
Thus the equation of the line passing through the point (3, 2, -4) and parallel to the line  L1 is:
fraction numerator straight x minus 3 over denominator negative 3 end fraction space equals space fraction numerator straight y minus 2 over denominator 1 end fraction space equals space fraction numerator straight z plus 4 over denominator 2 end fraction
 

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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.

140 Views

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