Directions Cosine and Ratios of Vector
Vector Algebra

87884 Let \(\vec{a}, \vec{b}, \vec{c}\) be three vectors such that \(\mathbf{c} \neq \mathbf{0}\) and \(\vec{a} \cdot \vec{b}=2 \vec{a} \cdot \vec{c},|\vec{a}|=|\vec{c}|=1,|\vec{b}|=4\) and \(|\vec{b} \times \vec{c}|=\) \(\sqrt{15}\), if \(b-2 c=\lambda \alpha\). then, \(\lambda\) equals

1 -1
2 1
3 -4
4 2
Vector Algebra

87885 If \(\vec{l}=3 \hat{\mathbf{i}}-\hat{\mathbf{j}}+2 \hat{\mathbf{k}}, \overrightarrow{\mathrm{m}}=\hat{\mathbf{i}}+\hat{\mathbf{j}}+2 \hat{\mathbf{k}}\) and \(\overrightarrow{\mathbf{n}}=\mathbf{2} \hat{\mathbf{i}}+\mathbf{2} \hat{\mathbf{j}}+\mathbf{2} \hat{\mathbf{k}}\) are three vectors, then what is the value of \(\lambda\) such that \(\vec{n}\) is perpendicular to \(\vec{\lambda}+\overrightarrow{\mathbf{m}}\) ?

1 1
2 -1
3 2
4 -2
Vector Algebra

87886 The vector \(\vec{a}=\alpha \hat{i}+2 \hat{j}+\beta \hat{k}\) lies in the plane of the vectors \(\overrightarrow{\mathbf{b}}=\hat{\mathbf{i}}+\hat{\mathbf{j}}\) and \(\overrightarrow{\mathbf{c}}=\hat{\mathbf{j}}+\hat{\mathbf{k}}\) and bisects the angle between \(\vec{b}\) and \(\vec{c}\). Then, which one of the following gives possible values of \(\alpha\) and \(\beta\) ?

1 \(\alpha=1, \beta=1\)
2 \(\alpha=2, \beta=2\)
3 \(\alpha=1, \beta=2\)
4 \(\alpha=2, \beta=1\)
Vector Algebra

87889 \(\vec{a}=\frac{1}{7}(2 \hat{i}+3 \hat{j}+6 \hat{k}), \vec{b}=\frac{1}{7}(3 \hat{i}-\lambda \hat{j}+2 \hat{k})\). If \(a\) and
\(b\) are mutually perpendicular, then value of \(\lambda\) is

1 2
2 -1
3 6
4 -6
Vector Algebra

87884 Let \(\vec{a}, \vec{b}, \vec{c}\) be three vectors such that \(\mathbf{c} \neq \mathbf{0}\) and \(\vec{a} \cdot \vec{b}=2 \vec{a} \cdot \vec{c},|\vec{a}|=|\vec{c}|=1,|\vec{b}|=4\) and \(|\vec{b} \times \vec{c}|=\) \(\sqrt{15}\), if \(b-2 c=\lambda \alpha\). then, \(\lambda\) equals

1 -1
2 1
3 -4
4 2
Vector Algebra

87885 If \(\vec{l}=3 \hat{\mathbf{i}}-\hat{\mathbf{j}}+2 \hat{\mathbf{k}}, \overrightarrow{\mathrm{m}}=\hat{\mathbf{i}}+\hat{\mathbf{j}}+2 \hat{\mathbf{k}}\) and \(\overrightarrow{\mathbf{n}}=\mathbf{2} \hat{\mathbf{i}}+\mathbf{2} \hat{\mathbf{j}}+\mathbf{2} \hat{\mathbf{k}}\) are three vectors, then what is the value of \(\lambda\) such that \(\vec{n}\) is perpendicular to \(\vec{\lambda}+\overrightarrow{\mathbf{m}}\) ?

1 1
2 -1
3 2
4 -2
Vector Algebra

87886 The vector \(\vec{a}=\alpha \hat{i}+2 \hat{j}+\beta \hat{k}\) lies in the plane of the vectors \(\overrightarrow{\mathbf{b}}=\hat{\mathbf{i}}+\hat{\mathbf{j}}\) and \(\overrightarrow{\mathbf{c}}=\hat{\mathbf{j}}+\hat{\mathbf{k}}\) and bisects the angle between \(\vec{b}\) and \(\vec{c}\). Then, which one of the following gives possible values of \(\alpha\) and \(\beta\) ?

1 \(\alpha=1, \beta=1\)
2 \(\alpha=2, \beta=2\)
3 \(\alpha=1, \beta=2\)
4 \(\alpha=2, \beta=1\)
Vector Algebra

87889 \(\vec{a}=\frac{1}{7}(2 \hat{i}+3 \hat{j}+6 \hat{k}), \vec{b}=\frac{1}{7}(3 \hat{i}-\lambda \hat{j}+2 \hat{k})\). If \(a\) and
\(b\) are mutually perpendicular, then value of \(\lambda\) is

1 2
2 -1
3 6
4 -6
NEET Test Series from KOTA - 10 Papers In MS WORD WhatsApp Here
Vector Algebra

87884 Let \(\vec{a}, \vec{b}, \vec{c}\) be three vectors such that \(\mathbf{c} \neq \mathbf{0}\) and \(\vec{a} \cdot \vec{b}=2 \vec{a} \cdot \vec{c},|\vec{a}|=|\vec{c}|=1,|\vec{b}|=4\) and \(|\vec{b} \times \vec{c}|=\) \(\sqrt{15}\), if \(b-2 c=\lambda \alpha\). then, \(\lambda\) equals

1 -1
2 1
3 -4
4 2
Vector Algebra

87885 If \(\vec{l}=3 \hat{\mathbf{i}}-\hat{\mathbf{j}}+2 \hat{\mathbf{k}}, \overrightarrow{\mathrm{m}}=\hat{\mathbf{i}}+\hat{\mathbf{j}}+2 \hat{\mathbf{k}}\) and \(\overrightarrow{\mathbf{n}}=\mathbf{2} \hat{\mathbf{i}}+\mathbf{2} \hat{\mathbf{j}}+\mathbf{2} \hat{\mathbf{k}}\) are three vectors, then what is the value of \(\lambda\) such that \(\vec{n}\) is perpendicular to \(\vec{\lambda}+\overrightarrow{\mathbf{m}}\) ?

1 1
2 -1
3 2
4 -2
Vector Algebra

87886 The vector \(\vec{a}=\alpha \hat{i}+2 \hat{j}+\beta \hat{k}\) lies in the plane of the vectors \(\overrightarrow{\mathbf{b}}=\hat{\mathbf{i}}+\hat{\mathbf{j}}\) and \(\overrightarrow{\mathbf{c}}=\hat{\mathbf{j}}+\hat{\mathbf{k}}\) and bisects the angle between \(\vec{b}\) and \(\vec{c}\). Then, which one of the following gives possible values of \(\alpha\) and \(\beta\) ?

1 \(\alpha=1, \beta=1\)
2 \(\alpha=2, \beta=2\)
3 \(\alpha=1, \beta=2\)
4 \(\alpha=2, \beta=1\)
Vector Algebra

87889 \(\vec{a}=\frac{1}{7}(2 \hat{i}+3 \hat{j}+6 \hat{k}), \vec{b}=\frac{1}{7}(3 \hat{i}-\lambda \hat{j}+2 \hat{k})\). If \(a\) and
\(b\) are mutually perpendicular, then value of \(\lambda\) is

1 2
2 -1
3 6
4 -6
Vector Algebra

87884 Let \(\vec{a}, \vec{b}, \vec{c}\) be three vectors such that \(\mathbf{c} \neq \mathbf{0}\) and \(\vec{a} \cdot \vec{b}=2 \vec{a} \cdot \vec{c},|\vec{a}|=|\vec{c}|=1,|\vec{b}|=4\) and \(|\vec{b} \times \vec{c}|=\) \(\sqrt{15}\), if \(b-2 c=\lambda \alpha\). then, \(\lambda\) equals

1 -1
2 1
3 -4
4 2
Vector Algebra

87885 If \(\vec{l}=3 \hat{\mathbf{i}}-\hat{\mathbf{j}}+2 \hat{\mathbf{k}}, \overrightarrow{\mathrm{m}}=\hat{\mathbf{i}}+\hat{\mathbf{j}}+2 \hat{\mathbf{k}}\) and \(\overrightarrow{\mathbf{n}}=\mathbf{2} \hat{\mathbf{i}}+\mathbf{2} \hat{\mathbf{j}}+\mathbf{2} \hat{\mathbf{k}}\) are three vectors, then what is the value of \(\lambda\) such that \(\vec{n}\) is perpendicular to \(\vec{\lambda}+\overrightarrow{\mathbf{m}}\) ?

1 1
2 -1
3 2
4 -2
Vector Algebra

87886 The vector \(\vec{a}=\alpha \hat{i}+2 \hat{j}+\beta \hat{k}\) lies in the plane of the vectors \(\overrightarrow{\mathbf{b}}=\hat{\mathbf{i}}+\hat{\mathbf{j}}\) and \(\overrightarrow{\mathbf{c}}=\hat{\mathbf{j}}+\hat{\mathbf{k}}\) and bisects the angle between \(\vec{b}\) and \(\vec{c}\). Then, which one of the following gives possible values of \(\alpha\) and \(\beta\) ?

1 \(\alpha=1, \beta=1\)
2 \(\alpha=2, \beta=2\)
3 \(\alpha=1, \beta=2\)
4 \(\alpha=2, \beta=1\)
Vector Algebra

87889 \(\vec{a}=\frac{1}{7}(2 \hat{i}+3 \hat{j}+6 \hat{k}), \vec{b}=\frac{1}{7}(3 \hat{i}-\lambda \hat{j}+2 \hat{k})\). If \(a\) and
\(b\) are mutually perpendicular, then value of \(\lambda\) is

1 2
2 -1
3 6
4 -6