Engineering mechanica MCQ (Law of Forces and Analysis)

 Engineering mechanica MCQ 

(Law of Forces and Analysis) 

1. The polygon law of forces states that if a

number of forces, acting simultaneously on a

particle, be represented in magnitude and

direction by the sides a polygon taken in order,

then their resultant is represented in magnitude

 and direction by the closing side of the polygon, 

taken in opposite direction:

(a) taken in opposite order 
(b) taken in same order 
(c) taken in any order 
(d) taken in opposite order not required 

Ans : (a)  (Law of Polygon of Forces 

2. A drum weighting 60 N and holding 40 kgf of
water is raised from a well by means of a wheel
and axle with an effort of 120 N. Its mechanical
advantage (MA) will be............
(a) 0.83              (b) 4.5
(c) 3.77              (d) 3

Ans : (c) 

3. The force applied on a body of mass 100kg to
produce an acceleration of 5 m/s2, is

(a) 20 N/20 
(b) 100 N/100 
(c) 500 N/500 
(d) None of these
Ans : (c) 

4. The law of parallelogram of forces gives the
resultant of 

(a) Parallel forces
(b) Two coplanar concurrent forces
(c) Like parallel forces
(d) Non Coplanar concurrent forces 

Ans : (b) 

5. The point of application of the resultant of all the forces which tends to cause rotation in the body about a certain axis is known as....

(a) center of gravity (b) the point of metacentre (c) point of suspension (d) centre of percussion

Ans : (d)  6. Which equilibrium is used for two forces? (a) Same line of action (b) Equal in magnitude (c) Opposite in direction  (d) All of the above options  Ans : (d) 7. If three coplanar concurrent forces acting at a point 'O' are in equilibrium, then ratio of forces T1/T2 & T1/T3 respectively are Ans : (a)  8. Two equal forces are acting at a point with an angle of 60° between them the resultant is 50 3 N, the magnitude of each force will be (a) 100 N              (b) 150 N (c) 50 N                (d) 79 N Ans : (c)  9. Two equal forces of magnitude 10 Newton act at an angle of 90°. Their resultant is equal to: (a) 10 N          (b) 10 √2 N (c) 10 √3 N     (d) 20 N Ans. (b) 10. Choose the CORRECT option regarding the effect of forces acting on the body? (a) Introduces internal stress. (b) Balance the other forces acting on it. (c) Retard its motion (d) All option are correct  Ans. (d)