Parallel Forces, Moment and Couples- Basic Level

Parallel Forces, Moment and Couples- Basic Level

Dear Readers,

Statics is the branch of mechanics that is concerned with the analysis of loads acting on physical systems that do not experience an acceleration, but rather, are in static equilibrium with their environment. .

Q1. Like parallel forces act at the vertices A, B and C of a triangle ABC and are proportional to the lengths BC, AC and AB respectively. The centre of the force is at the

•  Centroid
•  Circum- centre
•  Incentre
•  None of these

Solution
The centre of the force is at the Incentre

Q2.The resultant of two unlike parallel forces of magnitude P each acting at a distance of p is a

•  Force P
•  Couple of moment p.P
•  Force 2P
•  Force P/2

Solution
The resultant of two unlike parallel forces of magnitude P each acting at a distance of p is a Couple of moment p.P

Q3.  A rod can turn freely about one of its ends which is fixed. At the other end a horizontal force equal to half the weight of the body is acting. In the position of equilibrium, the rod is inclined to the vertical at an angle

•  30
•  45
•  60
•  None of these

Solution
the rod is inclined to the vertical at an angle 45

Q4. The resultant of two like parallel forces P, Q passes through a point O. If the resultant also passes through O when Q and R replace P and Q respectively, then

•  P,Q,R are in G.P.
•  Q,P,R are in G.P.
•  R,P,Q are in G.P.
•  P,Q,R are in A.P.

Solution
The resultant of two like parallel forces P, Q passes through a point O. If the resultant also passes through O when Q and R replace P and Q respectively, then P,Q,R are in G.P.

Q5.Any two coplanar couples of equal moments

•  Balance each other
•  Are equivalent
•  Need not be equivalent
•  None of these

Solution
 Any two coplanar couples of equal moments are equivalent

Q6. If the sum of the resolved parts of a system of coplanar forces along two mutually perpendicular direction is zero, then the sum of the moment of the forces about a given point

•  Is zero always
•  Is positive always
• Is negative always
•  May have any value

Solution
the sum of the moment of the forces about a given point May have any value

Q7.If the resultant of two unlike parallel forces of magnitudes 10 N and 16 N act along a line at a distance of 24 cm from the line of action of the smaller force, then the distance between the lines of action of the forces is

•  12 cm
•  8 cm
•  9 cm
•  18 cm

Solution
the distance between the lines of action of the forces is 9cm

Q8.If the position of the resultant of two like parallel forces P and Q is unaltered, when the positions of P and Q are interchanged, then

•  P=Q
•  P=2Q
•  2P=Q
•  None of these

Solution
If the position of the resultant of two like parallel forces P and Q is unaltered, when the positions of P and Q are interchanged, then P=Q

Q9.The resultant of two like parallel forces is 12N. The distance between the forces is 18m. If one of the force is 4N, then the distance of the resultant from the smaller force is

•  4m
•  8m
•  12m
•  None of these

Solution
the distance of the resultant from the smaller force is 12m

Q10. Force forming a couple are of magnitude 12N each and the arm of the couple is 8m. The force of an equivalent couple whose arm is 6m is of magnitude

•  8N
•  16N
•  12N
•  4N

Solution
The force of an equivalent couple whose arm is 6m is of magnitude 16N