**651. The rectangular coordinate system is also called______________?**

A. Polar coordinate system

**B. Cartesian coordinate system**

C. Cylindrical coordinate system

D. Spherical coordinate system

**652. Maximum number of rectangular components are_____________?**

A. 1

B. 2

**C. 3**

D. 4

**653. 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**

**654. Maximum number of components of a vector may be________________?**

A. 1

B. 2

C. 3

**D. Infinite**

**655. 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**

**656. 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°**

**657. Three coplanar forces acting on a body keep it in equilibrium. They should therefore be_______________?**

**A. Concurrent**

B. Non-concurrent

C. Parallel

D. Non-parallel

**658. Which of the following pairs does not have identical dimensions ?**

A. Torque and energy

B. Momentum and impulse

C. Energy and work

**D. Mass and moment of inertia**

**659. It is easier to turn a steering wheel with both hands than with a single hand because______________?**

A. Accelerating force increases on the wheel

B. Two forces act on the wheel

C. Two hands provide a firm grip

**D. The couple acts on the wheel**

**660. The cross product i^ x j^ is equal to_______________?**

A. Zero

B. One

C. i^

**D. k^**