Friday, September 10, 2021

HSC Vectors Solved MCQ : Maharashtra Board

 


VECTORS

Q.1. If the vectors i with hat on top minus 2 j with hat on top plus k with hat on top comma space a i with hat on top minus 5 j with hat on top plus 3 k with hat on top space a n d space 5 i with hat on top minus 9 j with hat on top plus 4 k with hat on top are coplanar, then the value of a is_______.

(A) 3

(B) -3

(C) 2

(D) -2


Q.2. If open vertical bar a with bar on top close vertical bar equals 3 comma space open vertical bar b with bar on top close vertical bar equals 4, then the value of lambda for which a with bar on top plus lambda b with bar on top is perpendicular to a with bar on top minus lambda b with bar on top comma is

(A)9 over 16

(B)3 over 4

(C) 3 over 2

(D) 4 over 3


Q.3. Let top enclose a equals i with hat on top minus j with hat on top comma space top enclose b equals j with hat on top minus k with hat on top comma space top enclose c equals k with hat on top minus i with hat on top. space I f space top enclose d is a unit vector such that top enclose a. top enclose d equals 0 equals open square brackets b with bar on top space top enclose c space top enclose d close square brackets comma space t h e n space top enclose d equals

(A) plus-or-minus fraction numerator i with hat on top plus j with hat on top minus 2 k with hat on top over denominator square root of 6 end fraction

(B)plus-or-minus fraction numerator i with hat on top plus j with hat on top minus k with hat on top over denominator square root of 3 end fraction

(C) plus-or-minus fraction numerator i with hat on top plus j with hat on top plus k with hat on top over denominator square root of 3 end fraction

(D) plus-or-minus k with hat on top


Q.4. If cos space alpha comma space cos space beta comma space cos space gamma are the direction cosines of a line, then the value of sin squared alpha plus sin squared beta plus sin squared gamma is

(A) 1

(B) 2

(C) 3

(D) 4


Q.5. If a line makes angles alpha comma space beta comma space gamma with co-ordinate axis, then sin squared alpha plus space sin squared beta plus sin squared gamma equals_______.

(A) 1

(B) -1

(C) 2

(D) -2


Q.6. If the vectors negative 3 i with hat on top plus 4 j with hat on top minus 2 k with hat on top comma space i with hat on top plus 2 k with hat on top comma space i with hat on top minus p j with hat on top are coplanar,, then the value of p is

(A) -2

(B) 1

(C) -1

(D) 2


Q.7. The volume of tetrahedron whose vertices are (1, -6, 10), (-1, -3, 7), (5, -1, lambda) and (7, -4, 7) is 11 cu. units, then the value of lambda is

(A) 7

(B) straight pi over 3

(C) 1

(D) 5


Q.8. If l, m, n are direction cosines of a line, then l space i with hat on top space plus space m space j with hat on top space plus space n k with hat on top is

(A) null vector

(B) the unit vector along the line

(C) any vector along the line

(D) a vector perpendicular to the line


Q.9. If open vertical bar a with bar on top close vertical bar equals 3 space a n d space minus 1 less or equal than k less or equal than 2 comma spacethen open vertical bar k a with bar on top close vertical bar lies in the interval

(A) open square brackets 0 comma space 6 close square brackets

(B) open square brackets negative 3 comma space 6 close square brackets

(C) open square brackets 3 comma space 6 close square brackets

(D) open square brackets 1 comma space 2 close square brackets


Q.10. The measure of acute angle between the lines whose direction ratios are 3, 2, 6 and -2, 1, 2 is _______.

(A) cos to the power of negative 1 end exponent open parentheses 1 over 7 close parentheses

(B) cos to the power of negative 1 end exponent open parentheses 8 over 15 close parentheses

(C) cos to the power of negative 1 end exponent open parentheses 1 half close parentheses

(D) cos to the power of negative 1 end exponent open parentheses 8 over 21 close parentheses


Q.11. If open vertical bar a with bar on top close vertical bar equals 2 comma space open vertical bar b with bar on top close vertical bar equals 3 comma space open vertical bar c with bar on top close vertical bar equals space 4 comma then open square brackets a with bar on top plus b with bar on top space b with bar on top space plus c with bar on top space c with bar on top plus a with bar on top close square brackets is equal to

(A) 24

(B) -24

(C) 0

(D) 48


Q.12. If sum of two unit vectors is itself a unit vector, then the magnitude of their difference is

(A) square root of 2

(B) square root of 3

(C) 1

(D) 2


Q.13. The line joining the points (-2, 1, -8) and (a, b, c) is parallel to the line whose direction ratios are 6, 2, 3. The values of a, b, c are

(A) 4, 3, -5

(B) 1 comma space 2 comma space fraction numerator negative 13 over denominator 2 end fraction

(C) 10, 5, -2

(D) 3, 5, 11


Q.14. The value of i with hat on top space. space open parentheses j with hat on top cross times k with hat on top close parentheses plus j with hat on top. open parentheses i with hat on top cross times k with hat on top close parentheses plus k with hat on top. space open parentheses i with hat on top cross times j with hat on top close parentheses is 

(A) 0

(B) -1

(C) 1

(D) 3


Q.15. Let a, b, c be distinct non-negative numbers. If the vectors a i with hat on top space plus space a j with hat on top space plus space c k with hat on top comma space i with hat on top space plus space k with hat on top and c i with hat on top space plus space c j with hat on top space plus space b k with hat on top lie in a plane, then c is

(A) the arithmetic mean of a and b

(B) the geometric mean of a and b

(C) the harmonic mean of a and b

(D) 0


Q.16. If open vertical bar a with bar on top close vertical bar equals 3 comma space open vertical bar b with bar on top close vertical bar equals 5 comma space open vertical bar c with bar on top close vertical bar equals 7 and a with bar on top plus b with bar on top plus c with bar on top equals 0 comma then the angle between a with bar on top and b with bar on top is

(A) straight pi over 2

(B) straight pi over 3

(C) straight pi over 4

(D) straight pi over 6


Q.17. If alpha comma space beta comma space gamma are direction angles of a line and alpha equals 60 to the power of ring operator comma space beta equals 45 to the power of ring operator, then gamma equals

(A) 30 to the power of ring operator space o r space 90 to the power of ring operator

(B) 45 to the power of ring operator space o r space 60 to the power of ring operator

(C) 90 to the power of ring operator space o r space 30 to the power of ring operator

(D) 60 to the power of ring operator space o r space 120 to the power of ring operator


Q.18. The distance of the point (3, 4, 5) from Y-axis is

(A) 3

(B) 5

(C) square root of 34

(D) square root of 41


Q.19. Let alpha comma space beta comma space gamma be distinct real numbers. The points with position vectors alpha space i with hat on top plus beta j with hat on top plus gamma space k with hat on top space comma space beta i with hat on top plus gamma j with hat on top plus alpha k with hat on top comma space gamma i with hat on top plus alpha j with hat on top plus beta k with hat on top

(A) are collinear

(B) form an equilateral triangle

(C) form a scalene triangle

(D) form a right angled triangle


Q.20. Let p with bar on top space a n d space q with bar on top be the position vectors of P and Q respectively, with respect to O and open vertical bar top enclose p close vertical bar equals space p comma space open vertical bar top enclose q close vertical bar equals q. The points R and S divide PQ internally and externally in the ratio 2 : 3 respectively. If OR and OS are perpendicular, then

(A) 9 p squared equals 4 q squared

(B) 4 p squared equals 9 q squared

(C) 9p = 4q

(D) 4p = 9q


Q.21. The 2 vectors j with hat on top plus k with hat on top and and 3 i with hat on top minus j with hat on top plus 4 k with hat on top represents the two sides AB and AC, respectively of a increment A B C. The length of the median through A is

(A) fraction numerator square root of 34 over denominator 2 end fraction

(B) fraction numerator square root of 48 over denominator 2 end fraction

(C) square root of 18

(D) None of these


Q.22. If top enclose a space a n d space top enclose b are unit vectors, then what is the angle between top enclose a space a n d space top enclose b space f o r space square root of 3 space top enclose a minus b with bar on top to be a unit vector?

(A) 30 to the power of ring operator

(B) 45 to the power of ring operator

(C) 60 to the power of ring operator

(D) 90 to the power of ring operator


Q.23. If theta be the angle between any two vectors top enclose a space a n d space top enclose b, then open vertical bar top enclose a. top enclose b close vertical bar equals open vertical bar top enclose a cross times top enclose b close vertical bar comma when theta is equal to

(A) 0

(B) straight pi over 4

(C) straight pi over 2

(D) straight pi


Q.24. If the vectors 2 i with hat on top space minus space q j with hat on top space plus space 3 k with hat on top space a n d space 4 i with hat on top space minus space 5 j with hat on top space plus 6 k with hat on top are collinear, then value of q is

(A) 5

(B) 10

(C) 5 over 2

(D) 5 over 4


Q.25. If top enclose a comma space top enclose b comma space top enclose c are non coplanar unit vectors such that top enclose a cross times open parentheses top enclose b cross times top enclose c close parentheses equals fraction numerator open parentheses top enclose b plus top enclose c close parentheses over denominator square root of 2 end fraction comma then the angle between top enclose a space a n d space top enclose b is 

(A) fraction numerator 3 straight pi over denominator 4 end fraction

(B) straight pi over 4

(C) straight pi over 2

(D) straight pi


Q.26. If a line is inclined at 60 to the power of ring operator and 30 to the power of ring operator with the X and Y-axis respectively, then the angle which it makes with Z-axis is

(A) 0

(B) straight pi over 4

(C) straight pi over 2

(D) straight pi over 6

Q.27. Which of the following represents direction cosines of the line?

(A) 0 comma fraction numerator 1 over denominator square root of 2 end fraction comma 1 half

(B) 0 comma fraction numerator negative square root of 3 over denominator 2 end fraction comma fraction numerator 1 over denominator square root of 2 end fraction

(C) 0 comma fraction numerator square root of 3 over denominator 2 end fraction comma 1 half

(D) 1 half comma 1 half comma 1 half


Q.28. If open square brackets top enclose a space top enclose b space top enclose c close square brackets not equal to 0 space a n d space top enclose p space equals fraction numerator top enclose b cross times top enclose c over denominator open square brackets top enclose a space top enclose b space top enclose c close square brackets end fraction comma space top enclose q equals fraction numerator top enclose c cross times top enclose a over denominator open square brackets top enclose a space top enclose b space top enclose c close square brackets end fraction comma space top enclose r equals fraction numerator top enclose a cross times top enclose b over denominator open square brackets top enclose a space top enclose b space top enclose c close square brackets end fraction comma space t h e n space top enclose a. top enclose p plus top enclose b. top enclose q plus top enclose c. top enclose r is equal to

(A) 0

(B) 1

(C) 2

(D) 3


Q.29. Direction cosines of the line passing through the points A(-4, 2, 3) and B(1, 3, -2) are

(A) plus-or-minus fraction numerator 1 over denominator square root of 51 end fraction comma space plus-or-minus fraction numerator 5 over denominator square root of 51 end fraction comma space plus-or-minus fraction numerator 1 over denominator square root of 51 end fraction

(B) plus-or-minus fraction numerator 5 over denominator square root of 51 end fraction comma space plus-or-minus fraction numerator 1 over denominator square root of 51 end fraction comma space plus-or-minus fraction numerator negative 5 over denominator square root of 51 end fraction

(C) plus-or-minus 5 comma space plus-or-minus 1 comma space plus-or-minus 5

(D)plus-or-minus square root of 51 comma space plus-or-minus square root of 51 comma space plus-or-minus square root of 51


Q.30. If the points A(2, 1, 1), B(0, -1, 4) and C(k, 3, -2) are collinear, then k=________.

(A) 0

(B) 1

(C) 4

(D) -4


Q.31. If top enclose a equals 3 i with hat on top minus j with hat on top plus 4 k with hat on top comma space top enclose b equals 2 i with hat on top plus 3 j with hat on top minus k with hat on top comma space top enclose c equals negative 5 i with hat on top plus 2 j with hat on top plus 3 k with hat on top comma space t h e n space top enclose a. open parentheses top enclose b cross times top enclose c close parentheses equals________.

(A) 100

(B) 101

(C) 110

(D) 109


Q.32. If a line makes angles 90 to the power of ring operator comma space 135 to the power of ring operator comma space 45 to the power of ring operator with the X, Y, Z axis respectively, then its direction cosines are_______.

(A) 0 comma fraction numerator 1 over denominator square root of 2 end fraction comma negative fraction numerator 1 over denominator square root of 2 end fraction

(B) 0 comma negative fraction numerator 1 over denominator square root of 2 end fraction comma negative fraction numerator 1 over denominator square root of 2 end fraction

(C) 1 comma fraction numerator 1 over denominator square root of 2 end fraction comma fraction numerator 1 over denominator square root of 2 end fraction

(D) 0 comma negative fraction numerator 1 over denominator square root of 2 end fraction comma fraction numerator 1 over denominator square root of 2 end fraction


Q.33. If a with bar on top equals 3 i with hat on top minus j with hat on top plus 4 k with hat on top comma space top enclose b equals 2 i with hat on top plus 3 j with hat on top minus k with hat on top space a n d space top enclose c equals negative 5 i with hat on top plus 2 j with hat on top plus 3 k with hat on top comma space t h e n space top enclose a. open parentheses top enclose b cross times top enclose c close parentheses is_______.

(A) 100

(B) 110

(C) 109

(D) 10


Q.34. The direction ratios of the line which is perpendicular to the lines with direction ratios -1, 2, 2 and 0, 2, 1 are______.

(A) -2, -1, -2

(B) 2, 1, 2

(C) 2, -1, -2

(D) -2, 1, -2


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