**Q: The angle of friction is :**

**(a) :**The ratio of the friction and the normal reaction

**(b) :**The force of friction when the body is in motion

**(c) :**The angle between the normal reaction and the resultant of normal raction and limiting friction

**(d) :**The force of friction at which the body is just about to move.

**(e) :**None of these

*The angle between the normal reaction and the resultant of normal raction and limiting friction*Explanation:

**Q: If the angle between the applied force and the direction of motion of a body, is between 90° and 180°, the work done, is called**

**(a) :**virtual work

**(b) :**imaginary work

**(c) :**zero work

**(d) :**negative work.

**(e) :**None of these

Answer:

Explanation:

*negative work.*Explanation:

**Q: The resolved part of the resultant of two forces inclined at an angle θ in a given direction is**

**(a) :**algebraic sum of the resolved parts of the forces in the direction

**(b) :**arithmetical sum of the resolved parts of the forces in the direction

**(c) :**difference of the forces multiplied by cosine θ°

**(d) :**sum of the forces multiplied by the sine θ

**(e) :**sum of the forces multiplied by the tangent θ°.

Answer:

Explanation:

*algebraic sum of the resolved parts of the forces in the direction*Explanation:

**Q: The centre of gravity of a triangle is at the point where three**

**(a) :**medians of the triangle mee

**(b) :**perpendicular bisectors of the sides of the triangle mee

**(c) :**bisectors of the angle of the triangle meet

**(d) :**all of these

**(e) :**None of these

Answer:

Explanation:

*medians of the triangle meet*Explanation: