Addition and Projection of Vectors
Vector Algebra

87786 If the sum of two unit vectors is a unit vector, then the magnitude of their difference is

1 \(\sqrt{2}\) units
2 2 units
3 \(\sqrt{3}\) units
4 \(\sqrt{5}\) units
Vector Algebra

87818 The work done by the force \(4 \hat{i}-3 \hat{j}+2 \hat{k}\) in moving a particle along a straight line from the point \((3,2,-1)\) to \((2,-1,4)\) is

1 0 unit
2 4 unit
3 15 unit
4 19 unit
Vector Algebra

87819 A parallelogram is constructed on the vectors \(\vec{a}=3 \alpha-\beta, \vec{b}=\alpha+3 \beta\). If \(|\alpha|=|\beta|=2\) and the angle between \(\alpha\) and \(\beta\) is \(\frac{\pi}{3}\), then length of a diagonal of the parallelogram is

1 \(4 \sqrt{3}\)
2 \(4 \sqrt{5}\)
3 \(4 \sqrt{7}\)
4 None of these
Vector Algebra

87728 If \(a, b, c\) are non- negative distinct numbers and \(\quad \hat{i}+\hat{\mathbf{j}}+\mathbf{c} \hat{\mathbf{k}}, \hat{\mathbf{i}}+\hat{\mathbf{k}}\) and \(\hat{\mathbf{i}}+\hat{\mathbf{j}}+\mathbf{b} \hat{\mathbf{k}}\) are coplanar vectors, then

1 a, b, c are in A.P
2 a, c, b are in A.P
3 a, c, b are in G.P
4 a, b, c are in G.P
Vector Algebra

87727 If \(\overrightarrow{\mathbf{a}}=2 \hat{i}-\hat{j}+\hat{k}, \vec{b}=\hat{i}+2 \hat{j}-3 \hat{k}\) and \(\overrightarrow{\mathbf{c}}=3 \hat{\mathbf{i}}+\lambda \hat{\mathbf{j}}+5 \hat{\mathbf{k}}\) are coplanar, then \(\lambda\) is the root of the equation

1 \(8-12=-4 \neq 6 \Rightarrow\) (b) \(16-8=8 \neq 4\)
2 \(x^2+2 x=4\)
3 \(16-12=4\)
\(\Rightarrow\) (d) \(16-8=8 \neq 6\)
Hence, \(\lambda=-4\) is the root of \(x^2+3 x=4\)
4 \(x^2+2 x=6\)
Vector Algebra

87786 If the sum of two unit vectors is a unit vector, then the magnitude of their difference is

1 \(\sqrt{2}\) units
2 2 units
3 \(\sqrt{3}\) units
4 \(\sqrt{5}\) units
Vector Algebra

87818 The work done by the force \(4 \hat{i}-3 \hat{j}+2 \hat{k}\) in moving a particle along a straight line from the point \((3,2,-1)\) to \((2,-1,4)\) is

1 0 unit
2 4 unit
3 15 unit
4 19 unit
Vector Algebra

87819 A parallelogram is constructed on the vectors \(\vec{a}=3 \alpha-\beta, \vec{b}=\alpha+3 \beta\). If \(|\alpha|=|\beta|=2\) and the angle between \(\alpha\) and \(\beta\) is \(\frac{\pi}{3}\), then length of a diagonal of the parallelogram is

1 \(4 \sqrt{3}\)
2 \(4 \sqrt{5}\)
3 \(4 \sqrt{7}\)
4 None of these
Vector Algebra

87728 If \(a, b, c\) are non- negative distinct numbers and \(\quad \hat{i}+\hat{\mathbf{j}}+\mathbf{c} \hat{\mathbf{k}}, \hat{\mathbf{i}}+\hat{\mathbf{k}}\) and \(\hat{\mathbf{i}}+\hat{\mathbf{j}}+\mathbf{b} \hat{\mathbf{k}}\) are coplanar vectors, then

1 a, b, c are in A.P
2 a, c, b are in A.P
3 a, c, b are in G.P
4 a, b, c are in G.P
Vector Algebra

87727 If \(\overrightarrow{\mathbf{a}}=2 \hat{i}-\hat{j}+\hat{k}, \vec{b}=\hat{i}+2 \hat{j}-3 \hat{k}\) and \(\overrightarrow{\mathbf{c}}=3 \hat{\mathbf{i}}+\lambda \hat{\mathbf{j}}+5 \hat{\mathbf{k}}\) are coplanar, then \(\lambda\) is the root of the equation

1 \(8-12=-4 \neq 6 \Rightarrow\) (b) \(16-8=8 \neq 4\)
2 \(x^2+2 x=4\)
3 \(16-12=4\)
\(\Rightarrow\) (d) \(16-8=8 \neq 6\)
Hence, \(\lambda=-4\) is the root of \(x^2+3 x=4\)
4 \(x^2+2 x=6\)
Vector Algebra

87786 If the sum of two unit vectors is a unit vector, then the magnitude of their difference is

1 \(\sqrt{2}\) units
2 2 units
3 \(\sqrt{3}\) units
4 \(\sqrt{5}\) units
Vector Algebra

87818 The work done by the force \(4 \hat{i}-3 \hat{j}+2 \hat{k}\) in moving a particle along a straight line from the point \((3,2,-1)\) to \((2,-1,4)\) is

1 0 unit
2 4 unit
3 15 unit
4 19 unit
Vector Algebra

87819 A parallelogram is constructed on the vectors \(\vec{a}=3 \alpha-\beta, \vec{b}=\alpha+3 \beta\). If \(|\alpha|=|\beta|=2\) and the angle between \(\alpha\) and \(\beta\) is \(\frac{\pi}{3}\), then length of a diagonal of the parallelogram is

1 \(4 \sqrt{3}\)
2 \(4 \sqrt{5}\)
3 \(4 \sqrt{7}\)
4 None of these
Vector Algebra

87728 If \(a, b, c\) are non- negative distinct numbers and \(\quad \hat{i}+\hat{\mathbf{j}}+\mathbf{c} \hat{\mathbf{k}}, \hat{\mathbf{i}}+\hat{\mathbf{k}}\) and \(\hat{\mathbf{i}}+\hat{\mathbf{j}}+\mathbf{b} \hat{\mathbf{k}}\) are coplanar vectors, then

1 a, b, c are in A.P
2 a, c, b are in A.P
3 a, c, b are in G.P
4 a, b, c are in G.P
Vector Algebra

87727 If \(\overrightarrow{\mathbf{a}}=2 \hat{i}-\hat{j}+\hat{k}, \vec{b}=\hat{i}+2 \hat{j}-3 \hat{k}\) and \(\overrightarrow{\mathbf{c}}=3 \hat{\mathbf{i}}+\lambda \hat{\mathbf{j}}+5 \hat{\mathbf{k}}\) are coplanar, then \(\lambda\) is the root of the equation

1 \(8-12=-4 \neq 6 \Rightarrow\) (b) \(16-8=8 \neq 4\)
2 \(x^2+2 x=4\)
3 \(16-12=4\)
\(\Rightarrow\) (d) \(16-8=8 \neq 6\)
Hence, \(\lambda=-4\) is the root of \(x^2+3 x=4\)
4 \(x^2+2 x=6\)
Vector Algebra

87786 If the sum of two unit vectors is a unit vector, then the magnitude of their difference is

1 \(\sqrt{2}\) units
2 2 units
3 \(\sqrt{3}\) units
4 \(\sqrt{5}\) units
Vector Algebra

87818 The work done by the force \(4 \hat{i}-3 \hat{j}+2 \hat{k}\) in moving a particle along a straight line from the point \((3,2,-1)\) to \((2,-1,4)\) is

1 0 unit
2 4 unit
3 15 unit
4 19 unit
Vector Algebra

87819 A parallelogram is constructed on the vectors \(\vec{a}=3 \alpha-\beta, \vec{b}=\alpha+3 \beta\). If \(|\alpha|=|\beta|=2\) and the angle between \(\alpha\) and \(\beta\) is \(\frac{\pi}{3}\), then length of a diagonal of the parallelogram is

1 \(4 \sqrt{3}\)
2 \(4 \sqrt{5}\)
3 \(4 \sqrt{7}\)
4 None of these
Vector Algebra

87728 If \(a, b, c\) are non- negative distinct numbers and \(\quad \hat{i}+\hat{\mathbf{j}}+\mathbf{c} \hat{\mathbf{k}}, \hat{\mathbf{i}}+\hat{\mathbf{k}}\) and \(\hat{\mathbf{i}}+\hat{\mathbf{j}}+\mathbf{b} \hat{\mathbf{k}}\) are coplanar vectors, then

1 a, b, c are in A.P
2 a, c, b are in A.P
3 a, c, b are in G.P
4 a, b, c are in G.P
Vector Algebra

87727 If \(\overrightarrow{\mathbf{a}}=2 \hat{i}-\hat{j}+\hat{k}, \vec{b}=\hat{i}+2 \hat{j}-3 \hat{k}\) and \(\overrightarrow{\mathbf{c}}=3 \hat{\mathbf{i}}+\lambda \hat{\mathbf{j}}+5 \hat{\mathbf{k}}\) are coplanar, then \(\lambda\) is the root of the equation

1 \(8-12=-4 \neq 6 \Rightarrow\) (b) \(16-8=8 \neq 4\)
2 \(x^2+2 x=4\)
3 \(16-12=4\)
\(\Rightarrow\) (d) \(16-8=8 \neq 6\)
Hence, \(\lambda=-4\) is the root of \(x^2+3 x=4\)
4 \(x^2+2 x=6\)
Vector Algebra

87786 If the sum of two unit vectors is a unit vector, then the magnitude of their difference is

1 \(\sqrt{2}\) units
2 2 units
3 \(\sqrt{3}\) units
4 \(\sqrt{5}\) units
Vector Algebra

87818 The work done by the force \(4 \hat{i}-3 \hat{j}+2 \hat{k}\) in moving a particle along a straight line from the point \((3,2,-1)\) to \((2,-1,4)\) is

1 0 unit
2 4 unit
3 15 unit
4 19 unit
Vector Algebra

87819 A parallelogram is constructed on the vectors \(\vec{a}=3 \alpha-\beta, \vec{b}=\alpha+3 \beta\). If \(|\alpha|=|\beta|=2\) and the angle between \(\alpha\) and \(\beta\) is \(\frac{\pi}{3}\), then length of a diagonal of the parallelogram is

1 \(4 \sqrt{3}\)
2 \(4 \sqrt{5}\)
3 \(4 \sqrt{7}\)
4 None of these
Vector Algebra

87728 If \(a, b, c\) are non- negative distinct numbers and \(\quad \hat{i}+\hat{\mathbf{j}}+\mathbf{c} \hat{\mathbf{k}}, \hat{\mathbf{i}}+\hat{\mathbf{k}}\) and \(\hat{\mathbf{i}}+\hat{\mathbf{j}}+\mathbf{b} \hat{\mathbf{k}}\) are coplanar vectors, then

1 a, b, c are in A.P
2 a, c, b are in A.P
3 a, c, b are in G.P
4 a, b, c are in G.P
Vector Algebra

87727 If \(\overrightarrow{\mathbf{a}}=2 \hat{i}-\hat{j}+\hat{k}, \vec{b}=\hat{i}+2 \hat{j}-3 \hat{k}\) and \(\overrightarrow{\mathbf{c}}=3 \hat{\mathbf{i}}+\lambda \hat{\mathbf{j}}+5 \hat{\mathbf{k}}\) are coplanar, then \(\lambda\) is the root of the equation

1 \(8-12=-4 \neq 6 \Rightarrow\) (b) \(16-8=8 \neq 4\)
2 \(x^2+2 x=4\)
3 \(16-12=4\)
\(\Rightarrow\) (d) \(16-8=8 \neq 6\)
Hence, \(\lambda=-4\) is the root of \(x^2+3 x=4\)
4 \(x^2+2 x=6\)