For what value of “a” , the magnitude of a vector A= 2i^+j^+ak^ should be 3?

Related Mcqs:

1. The unit vector in the direction of vector A = 2 i^ -2j^ + k^ is_______________?

   A. 2i^ – 2j^ + k^
   B. (2i^ – 2j^ +k^)/9
   C. (2i^ – 2j^ +k^)/3
   D. (2i^ – 2j^ +k^)/5

2. Two vectors A and B are making angle θ with each other. The scalar projection of vector B on vector A is written as____________?

   A. A.B/A
   B. A.B/B
   C. A.cosθ
   D. Both a and b are correct

3. Null vector is a vector which has________________?

   A. Zero magnitude
   B. No specified direction
   C. Both A and B are correct
   D. Both A and B are not correct

4. What is the minimum number of unequal magnitude vectors required to get a null vector?

   A. Zero
   B. Two
   C. Three
   D. None

   Submitted by: Zahid Jagirani

5. A vector can be multiplied by a number. The number may be_______________?

   A. Dimensionless
   B. Dimensional scalar
   C. Negative
   D. All A, B and C are correct

6. Unit vector n^ is along______________?

   A. X-axis
   B. Normal on a surface
   C. Y-axis
   D. Z-axis

7. The cross product of two vectors is a negative vector when______________?

   A. They are parallel vectors
   B. They are anti parallel vectors
   C. They are a perpendicular vector
   D. They are rotated through 270°

8. Which one is a unit vector ?

   A. ??3 i^ + ??3 j^ + ??3 k^
   B. 1/??3 i^ + 1/??3 j^ +1/ ??3 k^
   C. ??3 / 3 i^ + ??3 / 3 j^ + ??3 / 3 k^
   D. Both B and C are correct

9. Which one of the following is not vector quantity _______?

   A. Acceleration
   B. Displacement
   C. Speed
   D. Force

   Submitted by: Rashid Mehmood

10. A vector can have maximum________components in space.?

    A. Zero
    B. Two
    C. Three
    D. Infinite

    Submitted by: Zahid Jagirani