**831. The rectangular coordinate system is also called**

A. Polar coordinate system

**B. Cartesian coordinate system**

C. Cylindrical coordinate system

D. Spherical coordinate system

**832. The direction of a vector in space is specified by**

A. One angle

B. Two angle

**C. Three angle**

D. No angle

**833. Addition of vector obeys**

A. Commutative law

B. Distributive law

C. Associative law

**D. All given laws in A, B and C**

**834. 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**

**835.. Unit vector n^ is along**

A. X-axis

**B. Normal on a surface**

C. Y-axis

D. Z-axis

**836. Cosθi^ + Sinθj^ is a**

A. Vector

B. Position Vector

C. Vector in the direction at angle θ with an x-axis

**D. The unit vector in the direction at angle θ with an x-axis**

**837. Maximum number of rectangular components are**

A. 1

B. 2

**C. 3**

D. 4

**838. Maximum number of components of a vector may be**

A. 1

B. 2

C. 3

**D. Infinite**

**839. Which one is not correct for a vector A= 2i+2j+3k?**

A. Has direction 45° with an x-axis

B. Has magnitude 2

C. Has magnitude 2 and direction °=45° with a y-axis

**D. Has magnitude -2**

**840. The resultant of two forces of equal magnitudes is also equal to the magnitude of the forces. The angle between the two forces is**

A. 30°

B. 60°

C. 90°

**D. 120°**