Strength of Materials
According to principle of moments

if a system of coplanar forces is in equilibrium, then their algebraic sum is zero
if a system of coplanar forces is in equilibrium, then the algebraic sum of their moments about any point in their plane is zero
positive and negative couples can be balanced
the algebraic sum of the moments of any two forces about any point is equal to moment of theiwesultant about the same point

ANSWER DOWNLOAD EXAMIANS APP

Strength of Materials
Coefficient of friction is the

the friction force acting when the body is in motion
angle between normal reaction and the resultant of normal reaction and the limiting friction
ratio of limiting friction and normal reaction
the friction force acting when the body is just about to move

ANSWER DOWNLOAD EXAMIANS APP