500 Best Applied Mechanics MCQ
Q57). The following statement is one of the laws of Dynamic friction
a).The force of friction always acts in a direction opposite to that in which a body is moving
b).The magnitude of the kinetic friction bears a constant ratio to the normal reaction between two surfaces. The ratio being slightly less than that in the case of limiting friction
c).For moderate speeds the force of friction remains constant but decreases slightly with the increase of speed
d).all the above.
Correct Answer:
all the above.
Explanation:
Q58). A 50 kg boy climbs up a 8 m rope in gymnasiam in 10 sec. The average power developed by the boy is approximately
a).400 watts
b).500 watts
c).4000 watts
d).none of these.
Correct Answer:
400 watts
Explanation:
Q59). Lami’s theroem states that
a).three forces acting at a point are always in equilibrium
b).if three forces acting on a point can be represented in magnitude and direction by the sides of a triangle, the point will be in the state of equilibrium
c).three coplaner forces acting at a point will be in equilibrium, if each force is proportional to the sine of the angle between the other two
d).three coplaner forces acting at a point will be in equilibrium if each force is inversely proportional to the sine of the angle between the other two
Correct Answer:
three coplaner forces acting at a point will be in equilibrium, if each force is proportional to the sine of the angle between the other two
Explanation:
Q60). Pick up the incorrect statement from the following. In case of suspension bridge due to rise in temperature,
a).dip of the cable increases
b).length of the cable increases
c).dip of the cable decreases
d).none of the these.
Correct Answer:
dip of the cable decreases
Explanation:
Q61). If two forces acting at a point are in equilibrium, they must be equal in magnitude and their line of action must be along
a).the same line in the same sense
b).the same line in opposite sense
c).the perpendicular to both the lines
d).none of these.
Correct Answer:
the same line in opposite sense
Explanation:
Q62). For lifting a load of 50 kg through a distance of 2.5 cm, an effort of 12.5 kg is moved through a distance of 40 cm. The efficiency of the lifting machine, is
a).0.6
b).0.65
c).0.7
d).25%.
Correct Answer:
25%.
Explanation:
Q63). Power can be expressed as
a).work/energy
b).work/time
c).work x time
d).work/distance.
Correct Answer:
work/time
Explanation:
Q64). 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.
Correct Answer:
negative work.
Explanation: