Scalar (dot) Product of Vector
Vector Algebra

87966 If \(\vec{a}, \vec{b}, \vec{c}\) are unit vectors such that \(\vec{a}+\vec{b}+\vec{c}=\overrightarrow{0}\), then \(\overrightarrow{\mathbf{a}} \cdot \overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{b}} \cdot \overrightarrow{\mathbf{c}}+\overrightarrow{\mathbf{c}} \cdot \overrightarrow{\mathrm{a}}=\)

1 \(\frac{3}{2}\)
2 \(-\frac{3}{2}\)
3 \(\frac{2}{3}\)
4 \(\frac{1}{2}\)
Vector Algebra

87967 If \((\vec{a} \times \vec{b})^2+(a . \vec{b})^2=144\) and \(|\vec{a}|=4\), then \(|\vec{b}|=\)

1 12
2 16
3 8
4 3
Vector Algebra

87969 The projection of \(\vec{a}=3 \hat{i}-\hat{j}+5 \hat{k}\) on \(\overrightarrow{\mathrm{b}}=2 \hat{\mathrm{i}}+3 \hat{\mathbf{j}}+\hat{\mathrm{k}}\) is

1 \(\frac{8}{\sqrt{14}}\)
2 \(\sqrt{14}\)
3 \(\frac{8}{\sqrt{35}}\)
4 \(\frac{8}{\sqrt{39}}\)
Vector Algebra

87970 If \(\vec{a}\) is vector perpendicular to both \(\vec{b}\) and \(\overrightarrow{\mathbf{c}}\), then

1 \(\overrightarrow{\mathrm{a}}+(\overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
2 \(\overrightarrow{\mathrm{a}} \times(\overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
3 \(\overrightarrow{\mathrm{a}} \times(\overrightarrow{\mathrm{b}} \times \overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
4 \(\overrightarrow{\mathrm{a}} \cdot(\overrightarrow{\mathrm{b}} \times \overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
Vector Algebra

87966 If \(\vec{a}, \vec{b}, \vec{c}\) are unit vectors such that \(\vec{a}+\vec{b}+\vec{c}=\overrightarrow{0}\), then \(\overrightarrow{\mathbf{a}} \cdot \overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{b}} \cdot \overrightarrow{\mathbf{c}}+\overrightarrow{\mathbf{c}} \cdot \overrightarrow{\mathrm{a}}=\)

1 \(\frac{3}{2}\)
2 \(-\frac{3}{2}\)
3 \(\frac{2}{3}\)
4 \(\frac{1}{2}\)
Vector Algebra

87967 If \((\vec{a} \times \vec{b})^2+(a . \vec{b})^2=144\) and \(|\vec{a}|=4\), then \(|\vec{b}|=\)

1 12
2 16
3 8
4 3
Vector Algebra

87969 The projection of \(\vec{a}=3 \hat{i}-\hat{j}+5 \hat{k}\) on \(\overrightarrow{\mathrm{b}}=2 \hat{\mathrm{i}}+3 \hat{\mathbf{j}}+\hat{\mathrm{k}}\) is

1 \(\frac{8}{\sqrt{14}}\)
2 \(\sqrt{14}\)
3 \(\frac{8}{\sqrt{35}}\)
4 \(\frac{8}{\sqrt{39}}\)
Vector Algebra

87970 If \(\vec{a}\) is vector perpendicular to both \(\vec{b}\) and \(\overrightarrow{\mathbf{c}}\), then

1 \(\overrightarrow{\mathrm{a}}+(\overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
2 \(\overrightarrow{\mathrm{a}} \times(\overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
3 \(\overrightarrow{\mathrm{a}} \times(\overrightarrow{\mathrm{b}} \times \overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
4 \(\overrightarrow{\mathrm{a}} \cdot(\overrightarrow{\mathrm{b}} \times \overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
Vector Algebra

87966 If \(\vec{a}, \vec{b}, \vec{c}\) are unit vectors such that \(\vec{a}+\vec{b}+\vec{c}=\overrightarrow{0}\), then \(\overrightarrow{\mathbf{a}} \cdot \overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{b}} \cdot \overrightarrow{\mathbf{c}}+\overrightarrow{\mathbf{c}} \cdot \overrightarrow{\mathrm{a}}=\)

1 \(\frac{3}{2}\)
2 \(-\frac{3}{2}\)
3 \(\frac{2}{3}\)
4 \(\frac{1}{2}\)
Vector Algebra

87967 If \((\vec{a} \times \vec{b})^2+(a . \vec{b})^2=144\) and \(|\vec{a}|=4\), then \(|\vec{b}|=\)

1 12
2 16
3 8
4 3
Vector Algebra

87969 The projection of \(\vec{a}=3 \hat{i}-\hat{j}+5 \hat{k}\) on \(\overrightarrow{\mathrm{b}}=2 \hat{\mathrm{i}}+3 \hat{\mathbf{j}}+\hat{\mathrm{k}}\) is

1 \(\frac{8}{\sqrt{14}}\)
2 \(\sqrt{14}\)
3 \(\frac{8}{\sqrt{35}}\)
4 \(\frac{8}{\sqrt{39}}\)
Vector Algebra

87970 If \(\vec{a}\) is vector perpendicular to both \(\vec{b}\) and \(\overrightarrow{\mathbf{c}}\), then

1 \(\overrightarrow{\mathrm{a}}+(\overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
2 \(\overrightarrow{\mathrm{a}} \times(\overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
3 \(\overrightarrow{\mathrm{a}} \times(\overrightarrow{\mathrm{b}} \times \overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
4 \(\overrightarrow{\mathrm{a}} \cdot(\overrightarrow{\mathrm{b}} \times \overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
Vector Algebra

87966 If \(\vec{a}, \vec{b}, \vec{c}\) are unit vectors such that \(\vec{a}+\vec{b}+\vec{c}=\overrightarrow{0}\), then \(\overrightarrow{\mathbf{a}} \cdot \overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{b}} \cdot \overrightarrow{\mathbf{c}}+\overrightarrow{\mathbf{c}} \cdot \overrightarrow{\mathrm{a}}=\)

1 \(\frac{3}{2}\)
2 \(-\frac{3}{2}\)
3 \(\frac{2}{3}\)
4 \(\frac{1}{2}\)
Vector Algebra

87967 If \((\vec{a} \times \vec{b})^2+(a . \vec{b})^2=144\) and \(|\vec{a}|=4\), then \(|\vec{b}|=\)

1 12
2 16
3 8
4 3
Vector Algebra

87969 The projection of \(\vec{a}=3 \hat{i}-\hat{j}+5 \hat{k}\) on \(\overrightarrow{\mathrm{b}}=2 \hat{\mathrm{i}}+3 \hat{\mathbf{j}}+\hat{\mathrm{k}}\) is

1 \(\frac{8}{\sqrt{14}}\)
2 \(\sqrt{14}\)
3 \(\frac{8}{\sqrt{35}}\)
4 \(\frac{8}{\sqrt{39}}\)
Vector Algebra

87970 If \(\vec{a}\) is vector perpendicular to both \(\vec{b}\) and \(\overrightarrow{\mathbf{c}}\), then

1 \(\overrightarrow{\mathrm{a}}+(\overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
2 \(\overrightarrow{\mathrm{a}} \times(\overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
3 \(\overrightarrow{\mathrm{a}} \times(\overrightarrow{\mathrm{b}} \times \overrightarrow{\mathrm{c}})=\overrightarrow{0}\)
4 \(\overrightarrow{\mathrm{a}} \cdot(\overrightarrow{\mathrm{b}} \times \overrightarrow{\mathrm{c}})=\overrightarrow{0}\)