Three vectors A, B, and C add up to zero. Then:

1.	vector (A×B)×C is not zero unless vectors B and C are parallel.
2.	vector (A×B).C is not zero unless vectors B and C are parallel.
3.	if vectors A, B and C define a plane, (A×B)×C is in that plane.
4.	(A×B).C = |A||B||C|  → C2 = A2 + B2

The incorrect statement/s is/are:
1. (b, d)
2. (a, c)
3. (b, c, d)
4. (a, b)

The vector sum of two forces is perpendicular to their vector difference. In that case, the forces:

If the angle between the two forces increases, the magnitude of their resultant:

1. Decreases

2. Increases

3. Remains unchanged

4. First decreases, then increases

If $∆ABC$ is right-angled at C, then the value of cos (A + B) is:

                               
1. \(0\)
2. \(1\)
3. \(\frac{1}{2}\)
4. \(\frac{\sqrt{3}}{2}\)

Which of the following is not possible?
1. sin \(\theta\) = \(3\over5\)
2. sec \(\theta\) = \(100\)
3. cosec \(\theta\) = \(0.14\)
4. None of the above

Figure shows the orientation of two vectors \(u\) and \(v\) in the XY plane.
 If \(u = a\hat i + b\hat j\) and \(v = p\hat i + q\hat j\)

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Which of the following is correct?

The component of a vector \(r\) along the \(X\)-axis will have the maximum value if:

If the sum of two unit vectors is also a unit vector, then the magnitude of their difference and angle between the two given unit vectors is:
1. \(\sqrt{3}, 60^{\circ}\)
2. \(\sqrt{3}, 120^{\circ}\)
3. \(\sqrt{2}, 60^{\circ}\)
4. \(\sqrt{2},120^{\circ}\)

Let \(\theta\) be the angle between vectors \(\overrightarrow A\) and \(\overrightarrow {B}\). Which of the following figures correctly represents the angle \(\theta\)?

1.		2.
3.		4.

The dot product of two mutual perpendicular vector is:

1. \(0\)

2. \(1\)

3. \(\infty\)

4. None of the above