Civil Engineering

A. if a system of coplanar forces is in equilibrium, then their algebraic sum is zero

B. if a system of coplanar forces is in equilibrium, then the algebraic sum of their moments about any point in their plane is zero

C. the algebraic sum of the moments of any two forces about any point is equal to moment of theiwesultant about the same point

D. positive and negative couples can be balanced

A. W

B. W sin (a + $)

C. Wtan(a + <|))

D. Wan(a-)

A. 2n-3

B. n-l

C. ‘2n-l

D. n – 2

A. kilogram

B. newton

C. watt

D. dyne

A. their total sum is zero

B. two resolved parts in two directions at right angles are equal

C. sum of resolved parts in any two per-pendicular directions are both zero

D. all of them are inclined equally

A. meet in a point

B. be all parallel

C. at least two of them must meet

D. all the above are correct

A. L/2

B. L/3

C. 3L/4

D. 2L/3

A. if any number of forces acting at a point can be represented by the sides

of a polygon taken in order, then the forces are in equilibrium

B. if any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon, then the forces are in equilibrium

C. if a polygon representing forces acting at a point is closed then forces are in equilibrium

A. the tangent of the angle of friction is equal to coefficient of friction

B. the angle of repose is equal to angle of friction

C. the tangent of the angle of repose is equal to coefficient of friction

D. the sine of the angle of repose is equal to coefficient to friction

A. proportional to normal load between the surfaces

B. dependent on the materials of contact surface

C. proportional to velocity of sliding

D. independent of the area of contact surfaces