What will be the unit vector in the direction of \(\vec{A}=5 \vec{i}+\vec{j}-2 \vec{k} \text{?}\)
1. \(\dfrac{5}{\sqrt{30}} \vec{i}+\dfrac{1}{\sqrt{30}} \vec{j}+\dfrac{2}{\sqrt{30}} \vec{k}\)
2. \(\dfrac{5}{\sqrt{30}} \vec{i}+\dfrac{1}{\sqrt{30}} \vec{j}-\dfrac{2}{\sqrt{30}} \vec{k}\)
3. \(\dfrac{5}{\sqrt{30}} \vec{i}-\dfrac{1}{\sqrt{30}} \vec{j}-\dfrac{2}{\sqrt{30}} \vec{k}\)
4. \(\dfrac{5}{\sqrt{30}} \vec{i}-\dfrac{1}{\sqrt{30}} \vec{j}+\dfrac{2}{\sqrt{30}} \vec{k}\)
Subtopic:  Resolution of Vectors |
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If \(\overrightarrow {A}= 2\hat i + 4\hat j- 5\hat k,\) then the direction cosines of the vector are:

(direction cosines (or directional cosines) of a vector are the cosines of the angles between the vector and the three \(+\)ve coordinate axes.)
1. \(\frac{2}{\sqrt{45}}, \frac{4}{\sqrt{45}}~\text{and}~\frac{-5}{\sqrt{45}}\)
2. \(\frac{1}{\sqrt{45}}, \frac{2}{\sqrt{45}}~\text{and}~\frac{3}{\sqrt{45}}\)
3. \(\frac{4}{\sqrt{45}}, 0~\text{and}~\frac{4}{\sqrt{45}}\)
4. \(\frac{3}{\sqrt{45}}, \frac{2}{\sqrt{45}}~\text{and}~\frac{5}{\sqrt{45}}\)

Subtopic:  Resolution of Vectors |
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A force of \(20\) N acts on a particle along a direction, making an angle of \(60^\circ\) with the vertical. The component of the force along the vertical direction will be:

1. \(2\) N 2. \(5\) N
3. \(10\) N 4. \(20\) N
Subtopic:  Resolution of Vectors |
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A force of 5N acts on a particle along a direction making an angle of 60° with vertical. Its vertical component will be:

1. 10 N

2. 3 N

3. 4 N

4. 2.5 N

Subtopic:  Resolution of Vectors |
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\(\overrightarrow {A}\) is a vector with magnitude \(A\), then the unit vector \(\hat{A}\) in the direction of \(\overrightarrow {A}\) is:
1. \(A\overrightarrow A\)
2. \(\overrightarrow A \cdot\overrightarrow A\)
3. \(\overrightarrow A \times \overrightarrow A\)
4. \(\frac{\overrightarrow A}{A}\)
Subtopic:  Resolution of Vectors |
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