St. Britto Hr. Sec. School - Madurai
12th Maths Monthly Test - 1 ( Applications of Vector Algebra )-Aug 2020
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If the vectors \(a\overset { \wedge }{ i } +\overset { \wedge }{ j } +\overset { \wedge }{ k } \), \(\overset { \wedge }{ i } +b\overset { \wedge }{ j } +\overset { \wedge }{ k } \) and \(\overset { \wedge }{ i } +\overset { \wedge }{ j } +c\overset { \wedge }{ k } \) (a ≠ b ≠ c ≠ 1) are coplaner, then \(\frac { 1 }{ 1-a } +\frac { 1 }{ 1-b } +\frac { 1 }{ 1-c } =\)
0
1
2
\(\frac { abc }{ (1-a)(1-b)(1-c) } \)
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If a vector \(\vec { \alpha } \) lies in the plane of \(\vec { \beta } \) and \(\vec { \gamma } \) , then
\([\vec { \alpha } ,\vec { \beta } ,\vec { \gamma } ]\) = 1
\([\vec { \alpha } ,\vec { \beta } ,\vec { \gamma } ]\)= -1
\([\vec { \alpha } ,\vec { \beta } ,\vec { \gamma } ]\)= 0
\([\vec { \alpha } ,\vec { \beta } ,\vec { \gamma } ]\)= 2
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If \(\vec { a } ,\vec { b } ,\vec { c } \) are three unit vectors such that \(\vec { a } \) is perpendicular to \(\vec { b } \) and is parallel to \(\vec { c } \) then \(\vec { a } \times (\vec { b } \times \vec { c } )\) is equal to
\(\vec { a } \)
\(\vec { b} \)
\(\vec { c } \)
\(\vec { 0 } \)
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The length of the 丄r from the origin to plane \(\overset { \rightarrow }{ r } .\left( \overset { \wedge }{ 3i } +4\overset { \wedge }{ j } +12\overset { \wedge }{ k } \right) \)= 26 is _____________
2
\(\frac { 1 }{ 2 } \)
26
\(\frac { 26 }{ 169 } \)
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The angle between the planes 2x + y - z = 9 and x + 2y + z = 7 is_____________
cos-1 (5/6)
cos-1 (5/36)
cos-1 (1/2)
cos-1 (1/12)
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If \(\left| \overset { \rightarrow }{ a } \right| =\left| \overset { \rightarrow }{ b } \right| =1\)such that \(\overset { \rightarrow }{ a } +2\overset { \rightarrow }{ b } \) and \(5\overset { \rightarrow }{ a } -\overset { \rightarrow }{ b } \) are perpendicular to each other, then the angle between \(\overset { \rightarrow }{ a } \) and \(\overset { \rightarrow }{ b } \) is
45o
60o
cos-1 \(\left( \frac { 1 }{ 3 } \right) \)
cos-1 \(\left( \frac { 2 }{ 7 } \right) \)
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If \(\vec { a } ,\vec { b } ,\vec { c } \) are three non-coplanar vectors such that \(\vec { a } \times (\vec { b } \times \vec { c } )=\frac { \vec { b } +\vec { c } }{ \sqrt { 2 } } \), then the angle between
\(\frac { \pi }{ 2 } \)
\(\frac { 3\pi }{ 4 } \)
\(\frac { \pi }{ 4 } \)
\( { \pi }\)
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The distance between the planes x + 2y + 3z + 7 = 0 and 2x + 4y + 6z + 7 = 0
\(\frac { \sqrt { 7 } }{ 2\sqrt { 2 } } \)
\(\frac{7}{2}\)
\(\frac { \sqrt { 7 } }{ 2 } \)
\(\frac { 7 }{ 2\sqrt { 2 } } \)
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The vector equation \(\vec { r } =(\hat { i } -2\hat { j } -\hat { k } )+t(6\hat { i } -\hat { k) } \) represents a straight line passing through the points
(0,6,1)− and (1,2,1)
(0,6,-1) and (1,4,2)
(1,-2,-1) and (1,4,-2)
(1,-2,-1) and (0,-6,1)
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The area of the parallelogram having diagonals \(\overset { \rightarrow }{ a } =\overset { \wedge }{ 3i } +\overset { \wedge }{ j } -2\overset { \wedge }{ k } \) and \(\overset { \rightarrow }{ b } =\overset { \wedge }{ i } -3\overset { \wedge }{ j } +4\overset { \wedge }{ k } \) is _______________
4
\(2\sqrt { 3 } \)
\(4\sqrt { 3 } \)
\(5\sqrt { 3 } \)
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If the work done by a force \(\overset { \rightarrow }{ F } =\overset { \wedge }{ i } +m\overset { \wedge }{ j } -\overset { \wedge }{ k } \) in moving the point of application from(1, 1, 1) to (3, 3, 3) along a straight line is 12 units, then m is
5
2
3
6
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If \(\overset { \rightarrow }{ a } \) and \(\overset { \rightarrow }{ b } \) are two unit vectors, then the vectors \(\left( \overset { \rightarrow }{ a } +\overset { \rightarrow }{ b } \right) \times \left( \overset { \rightarrow }{ a } \times \overset { \rightarrow }{ b } \right) \) is parallel to the vector
\(\overset { \rightarrow }{ a } -\overset { \rightarrow }{ b } \)
\(\overset { \rightarrow }{ a } +\overset { \rightarrow }{ b } \)
2\(\overset { \rightarrow }{ a } -\overset { \rightarrow }{ b } \)
2\(\overset { \rightarrow }{ a } +\overset { \rightarrow }{ b } \)
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If \(\overset { \rightarrow }{ p } \times \overset { \rightarrow }{ q } =2\overset { \wedge }{ i } +3\overset { \wedge }{ j } \), \(\overset { \rightarrow }{ r } \times \overset { \rightarrow }{ s } =3\overset { \wedge }{ i } +2\overset { \wedge }{ k } \) then \(\overset { \rightarrow }{ p } .\left( \overset { \rightarrow }{ q } \left( \overset { \rightarrow }{ r } \times \overset { \rightarrow }{ s } \right) \right) \) is
9
6
2
5
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Forces of magnit \(5\sqrt { 2 } \) and \(5\sqrt { 2 } \) units acting in the directions \(\hat { 3i } +\hat { 4j } +\hat { 5k } \) and \(\hat { 10i } +\hat { 6j } -\hat { 8k } \) respectively, act on a particle which is displaced from the point with position vector \(\hat { 4i } +\hat { 3j } -\hat { 2k } \) to the point with position vector \(\hat { 6i } +\hat { j } -\hat { 3k } \). Find the work done by the forces.
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A particle acted on by constant forces \(8\hat i+2\hat j-6\hat k\) and \(6\hat i+2\hat j -2\hat k\) is displaced from the point (1, 2, 3) to the point (5, 4, 1). Find the total work done by the forces.
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Find the point of intersection of the line x - 1 = \(\frac { y }{ 2 } \) = z + 1 with the plane 2x - y + 2z = 2. Also, find the angle between the line and the plane.
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Show that the lines \(\frac { x-1 }{ 4 } =\frac { 2-y }{ 6 } =\frac { z-4 }{ 12 } \) and \(\frac { x-3 }{ -2 } =\frac { y-3 }{ 3 } =\frac { 5-z }{ 6 } \) are parallel.
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Find the angle between the following lines.
\(\frac { x+4 }{ 3 } =\frac { y-7 }{ 4 } =\frac { z+5 }{ 5 } \), \(\vec { r } =4\hat { k } +t(2\hat { i } +\hat { j } +\hat { k } )\)
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Find the direction cosines of the normal to the plane 12x + 3y − 4z = 65 . Also, find the non-parametric form of vector equation of a plane and the length of the perpendicular to the plane from the origin.
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Let \(\vec { a } ,\vec { b } ,\vec { c } \) be three non-zero vectors such that \(\vec { c } \) is a unit vector perpendicular to both \(\vec { a } \) and \(\vec { b } \). If the angle between \(\vec { a } \) and \(\vec { b } \) is \(\frac { \pi }{ 6 } \), show that \({ [\vec { a } ,\vec { b } ,\vec { c } ] }^{ 2 }\) = \(\frac { 1 }{ 4 } { \left| \vec { a } \right| }^{ 2 }{ \left| \vec { b } \right| }^{ 2 }\)
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If the straight lines \(\frac { x-1 }{ 2 } =\frac { y+1 }{ \lambda } =\frac { z }{ 2 } \) and \(\frac { x+1 }{ 2 } =\frac { y+1 }{ \lambda } =\frac { z }{ \lambda } \) are coplanar, find λ and equations of the planes containing these two lines.
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Find the torque of the resultant of the three forces represented by \(-3\hat { i } +6\hat { j } +3\hat { k } \), \(4\hat { i } -10\hat { j } +12\hat { k } \) and \(\hat { 4i } +\hat { 7j } \) acting at the point with position vector \(8\hat { i } -6\hat { j } -4\hat { k } \), about the point with position vector \(18\hat { i } +3\hat { j } -9\hat { k } \)
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Find the parametric form of vector equation of the straight line passing through (−1, 2,1) and parallel to the straight line \(\vec { r } =(2\hat { i } +3\hat { j } -\hat { k } )+t(\hat { i } -2\hat { j } +\hat { k } )\) and hence find the shortest distance
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If the planes \({ \overset { \rightarrow }{ r } }.\left( \overset { \wedge }{ i } +2\overset { \wedge }{ j } +3\overset { \wedge }{ k } \right) =7\)=and \({ \overset { \rightarrow }{ r } }.\left( \lambda \overset { \wedge }{ i } +2\overset { \wedge }{ j } -7\overset { \wedge }{ k } \right) =26\) are perpendicular. Find the value of λ.
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If the straight lines \(\frac { x-1 }{ 1 } =\frac { y-2 }{ 1 } =\frac { z-3 }{ { m }^{ 2 } } \) and \(\frac { x-3 }{ 1 } =\frac { y-2 }{ { m }^{ 2 } } =\frac { z-1 }{ 2 } \) are coplanar, find the distinct real values of m.
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Find the magnitude and direction cosines of the torque of a force represented by \(3\hat { i } +4\hat { j } -5\hat { k } \) about the point with position vector \(2\hat { i } -3\hat { j } +4\hat { k } \) acting through a point whose position vector is \(4\hat { i } +2\hat { j } -3\hat { k } \).
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Find the parametric form of vector equation and Cartesian equations of a straight line passing through (5, 2,8) and is perpendicular to the straight lines
\(\vec { r } =(\hat { i } +\hat { j } -\hat { k } )+s(2\hat { i } -2\hat { j } +\hat { k } )\)
\(\vec { r } =(\hat { 2i } -\hat { j } -3\hat { k } )+t(\hat { i } +2\hat { j } +2\hat { k } )\). -
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Find the parametric form of vector equation, and Cartesian equations of the plane containing the line \(\vec { r } =(\hat { i } -\hat { j } +3\hat { k } )+t(2\hat { i } -\hat { j } +4\hat { k } )\) and perpendicular to plane \(\vec { r } .(\hat { i } +2\hat { j } +\hat { k } )=8\)
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Find the equation of the plane passing through the line of intersection of the planes \(\vec { r } .(2\hat { i } -7\hat { j } +4\hat { k } )=3\) and 3x - 5y +4z + 11 = 0, and the point (-2, 1, 3)
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Prove by vector method that the area of the quadrilateral ABCD having diagonals AC and \(\frac { 1 }{ 2 } \left| \vec { AC } \times \vec { BC } \right| \).
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Find the angle between the lines \(\vec { r } =(\hat { i } +2\hat { j } +4\hat { k } )+t(2\hat { i } +2\hat { j } +\hat { k } )\) and the straight line passing through the points (5, 1, 4) and (9, 2, 12)
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If \(\overset { \rightarrow }{ a } +\overset { \rightarrow }{ b } +\overset { \rightarrow }{ c } =0\) then show that \(\overset { \rightarrow }{ a } \times \overset { \rightarrow }{ b } =\overset { \rightarrow }{ b } \times \overset { \rightarrow }{ c } =\overset { \rightarrow }{ c } \times \overset { \rightarrow }{ a } \)
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Find the angle between the line \(\frac { x-2 }{ 3 } =\frac { y-1 }{ -1 } =\frac { z-3 }{ 2 } \) and the plane 3x + 4y + z + 5 = 0
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Find the equation of the plane passing through the intersection of the planes \(\vec { r } .(\hat { i } +\hat { j } +\hat { k } )+1=0\) and \(\vec { r } .(2\hat { i } -3\hat { j } +5\hat { k } )=2\) and the point (-1, 2, 1)
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Prove that \([\vec { a } \times \vec { b } ,\vec { b } \times \vec { c } ,\vec { c } \times \vec { a } ]\) = \([{ \vec { a } ,\vec { b } ,\vec { c } }]^{ 2 }\)
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A straight line passes through the point (1, 2, −3) and parallel to \(4\hat { i } +5\hat { j } -7\hat { k } \). Find
(i) vector equation in parametric form
(ii) vector equation in non-parametric form
(iii) Cartesian equations of the straight line. -
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Show that the lines \(\frac { x-1 }{ 3 } =\frac { y+1 }{ 2 } =\frac { z-1 }{ 5 } \) and \(\frac { x+2 }{ 4 } =\frac { y-1 }{ 3 } =\frac { z+1 }{ -2 } \) do not intersect
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Find the equation of the plane through the intersection of the planes 2x-3y+ z-4 -0 and x - y + Z + 1 - 0 and perpendicular to the plane x + 2y - 3z + 6 = 0
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Find the magnitude and the direction cosines of the torque about the point (2, 0, -1) of a force \((\hat { 2i } +\hat { j } -\hat { k } )\), whose line of action passes through the origin
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With usual notations, in any triangle ABC, prove the following by vector method.
(i) a2=b2+c2−2bc cos A
(ii) b2=c2+a2−2ca cos B
(iii) c2= a2+b2−2ab cos C -
With usual notations, in any triangle ABC, prove the following by vector method.
(i) a=bcosC+ccos B
(ii) b=ccosA+acosC
(iii) c=acosB+bcos A -
Find the non-parametric form of vector equation, and Cartesian equation of the plane passing through the point (0, 1, -5) and parallel to the straight lines \(\vec { r } =(\hat { i } +2\hat { j } -4\hat { k } )+s(\hat { i } +3\hat { j } +6\hat { k } )\) and \(\hat { r } =(\hat { i } -3\hat { j } +5\hat { k } )+t(\hat { i } +\hat { j } -\hat { k } )\)
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Find the image of the point whose position vector is \(\hat { i } +2\hat { j } +3\hat { k } \) in the plane \(\vec { r } .(\hat { i } +2\hat { j } +4\hat { k } )\) = 38
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ABCD is a quadrilateral with \(\overset { \rightarrow }{ AB } =\overset { \rightarrow }{ \alpha } \) and \(\overset { \rightarrow }{ AD } =\overset { \rightarrow }{ \beta } \) and \(\overset { \rightarrow }{ AC } =2\overset { \rightarrow }{ \alpha } +3\overset { \rightarrow }{ \beta } \). If. the area of the quadrilateral is λ times the area of the parallelogram with \(\overset { \rightarrow }{ AB } \) and \(\overset { \rightarrow }{ AD } \) as adjacent sides, then prove that \(\lambda =\frac { 5 }{ 2 } \)
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If the Cartesian equation of a plane is 3x - 4y + 3z = -8, find the vector equation of the plane in the standard form.
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If \(\left| \overset { \rightarrow }{ A } \right| =\overset { \wedge }{ i } +\overset { \wedge }{ j } +\overset { \wedge }{ k } \) and \(\overset { \wedge }{ i } =\overset { \wedge }{ j } -\overset { \wedge }{ k } \) are two given vector, then find a vector B satisfying the equations \(\overset { \rightarrow }{ A } \times \overset { \rightarrow }{ B } \)= \(\overset { \rightarrow }{ C } \) and \(\overset { \rightarrow }{ A } \).\(\overset { \rightarrow }{ B } \)=3
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Show that the points A, B, C with position vector \(2\overset { \wedge }{ i } -\overset { \wedge }{ j } +\overset { \wedge }{ k } ,\overset { \wedge }{ i } -3\overset { \wedge }{ j } -5\overset { \wedge }{ k } \) and \(3\overset { \wedge }{ i } -4\overset { \wedge }{ j } +4\overset { \wedge }{ k } \) respectively are the vector of a right angled, triangle. Also, find the remaining angles of the triangle.
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Find the point of intersection of the lines \(\frac { x-1 }{ 2 } =\frac { y-2 }{ 3 } =\frac { z-3 }{ 4 } \) and \(\frac { x-4 }{ 5 } =\frac { y-1 }{ 2 } =z\)