# Chapter 8: Vector Algebra I - Online Test

Q1.

If are the position vectors of three collinear points, then which of the following is true?

Answer : Option B
Explaination / Solution: Q2. If , then the point P whose position vector divides the line joining the points with position vectors and in the ratio
Answer : Option A
Explaination / Solution: Q3. If λiˆ + 2λjˆ + 2λkˆ is a unit vector, then the value of λ is
Answer : Option A
Explaination / Solution: Q4. Two vertices of a triangle have position vectors 3iˆ + 4 ˆj − 4kˆ and 2iˆ + 3 ˆj + 4kˆ. If the position vector of the centroid is iˆ + 2 ˆj + 3kˆ, then the position vector of the third vertex is
Answer : Option A
Explaination / Solution: Q5. If  |  | = 60,|  | = 40 and | |=46, then | | is
Answer : Option C
Explaination / Solution: Q6. If and having same magnitude and angle between them is 60º and their scalar product is 1/2 then | | is
Answer : Option D
Explaination / Solution: Q7. The value of θ (0, π/2) for which the vectors are perpendicular, is equal to
Answer : Option A
Explaination / Solution: Q8. If | |= 13,| |= 5 and ⋅ = 60° then | × | is
Answer : Option D
Explaination / Solution: Q9. Vectors and are inclined at an angle θ = 120º. If | |= 1,| |= 2 , then [( + 3 ) × ( − )]2  is equal to
Answer : Option D
Explaination / Solution: Q10. If and are two vectors of magnitude 2 and inclined at an angle 60º , then the angle between and + is
Answer : Option A
Explaination / Solution: 