List Of Engineering Mechanics Objective Questions
1.20. The weight of a body is due to
centripetal force of earth
gravitational pull exerted by the earth
forces experienced by body in atmos-phere
force of attraction experienced by par-ticles
gravitational force of attraction towards the centre of the earth.
ANSWER : : gravitational force of attraction towards the centre of the earth.
2.26. The magnitude of two forces, which when acting at right angle produce resultant force of VlOkg and when acting at 60� produce resultant of Vl3 kg. These forces are
2 and V6
3 and 1 kg
V5andV5
2 and 5
none of the above.
ANSWER : : V5andV5
3.4. Forces are called concurrent when their lines of action meet in
one point
two points
plane
perpendicular planes
different planes.
ANSWER : : one point
4.19. Which of the following is not the unit of pressure ?
kg/cm
ata
atmosphere
mm of wcl
newton.
ANSWER : : newton.
5.18. Which of the following is not the unit of work, energy and heat ?
kcal
kg m
kWhr
hp
hp hr.
ANSWER : : hp
6.5. Forces are called coplanar when all of them acting on body lie in
one point
one plane
different planes
perpendicular planes
different points.
ANSWER : : one plane
7.17. Which of the following is not the unit of power ?
kW (kilowatt)
hp (horse power)
kcal/sec
kg m/sec
kcal/kg sec.
ANSWER : : kcal/kg sec.
8.15. Which of the following do not have identical dimensions ?
Momentum and impulse
Torque and energy
Torque and work
Kinetic energy and potential energy
Moment of a force and angular momentum.
ANSWER : : Moment of a force and angular momentum.
9.2. The unit of work or energy in S.I. units is
newton
pascal
kilogram metre
watt
joule.
ANSWER : : joule.
10.3. The unit of power in S.I. units is
newton metre
watt
joule
kilogram metre/sec.
pascal per sec.
ANSWER : : watt
11.16. Which of the following is not the unit of distance ?
angstrom
light year
micron
millimetre
milestone.
ANSWER : : milestone.
12.8. Effect of a force on a body depends upon
magnitude
direction
position or line of action
all of the above
none of the above.
ANSWER : : all of the above
13.7. Which is the correct statement about law of polygon of forces ?
if any number of forces acting at a point can be represented by the sides
polygon taken in order, then the forces are in equilibrium
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 equi�librium
if a polygon representing forces acting at a point is closed then forces are in equilibrium
ANSWER : 4 if any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon taken in order, then the forces are in equilibrium
14.6. A force acting on a body may
introduce internal stresses
balance the other forces acting on it
retard its motion
change its motion
all of the above.
ANSWER : : all of the above.
15.25. Which of the following is a vector quantity
energy
mass
momentum
angle
speed.
ANSWER : : momentum
16.11. A force is completely defined when we specify
magnitude
direction
point of application
all of the above
none of the above.
ANSWER : : all of the above
17.21. The forces, which meet at one point, but their lines of action do not lie in a plane, are called
coplanar non-concurrent forces
non-coplanar concurrent forces
non-coplanar non-concurrent forces
intersecting forces
none of the above.
ANSWER : : non-coplanar concurrent forces
18.22. When trying to turn a key into a lock, following is applied
coplanar force
non-coplanar forces
lever
moment
couple.
ANSWER : : couple.
19.13. The algebraic sum of the resolved parts of a number of forces in a given direction is equal to the resolved part of their resultant in the same direction. This is as per the principle of
forces
independence of forces
dependence of forces
balance of force
resolution of forces.
ANSWER : : resolution of forces.
20.12. If two equal forces of magnitude P act at an angle 9�, their resultant will be
P/2 cos 9/2
IP sin 9/2
2P tan 9/2
IP cos 9/2
Psin 9/2.
ANSWER : : IP cos 9/2
21.23. Which of the following is not a scalar quantity
time
mass
volume
density
acceleration.
ANSWER : : acceleration.
22.9. If a number of forces act simultaneously on a particle, it is possible
not a replace them by a single force
to replace them by a single force
to replace them by a single force through C.G.
to replace them by a couple
to replace them by a couple and a force.
ANSWER : : to replace them by a single force
23.24. According to principle of transmissibility of forces, the effect of a force upon a body is
maximum when it acts at the centre of gravity of a body
different at different points in its line of action
the same at every point in its line of action
minimum when it acts at the C.G. of the body
none of the above.
ANSWER : : the same at every point in its line of action
24.14. The resolved part of the resultant of two forces inclined at an angle 9 in a given direction is equal to
the algebraic sum of the resolved parts of the forces in the given direction
the sum of the resolved parts of the forces in the given direction
the difference of the forces multiplied by the cosine of 9
the sum of the forces multiplied by the sine of 9
the sum of the forces multiplied by the tangent of 9.
ANSWER : : the algebraic sum of the resolved parts of the forces in the given direction