ENGINEERING MECHANICS
1. A force is completely defined when we specify
(a) magnitude
(b) direction
(c) point of application
(d) all of the above
2. Which one of the following is not a scalar
quantity?
(a) Volume
(b) Mass
(c) Force
(d) Length
3. 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 known as-
3. 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 known as-
(a) Principle of resolution of forces
(b) All of the options
(c) Principle of transmissibility of forces
(d) Principle of independence of forces
4. Action and reaction act on–
(a) Different bodies but in same direction
(b) Same body but in opposite direction
(c) Same body and in same direction
(d) Different bodies but in opposite direction
5. According to Lami's theorem :
(a) the three forces must be equal
(b) the three forces must be at 120 to each other
(c) the three forces must be in equilibrium
(d) if the three forces acting at a point are in
equilibrium, then each force is proportional to
the sine of the angle between the other two
6. According to the principle of moments-
(a) If a system of coplanar forces is in
equilibrium, then their algebraic sum is zero
(b) Positive and negative couples can be balanced
(c) If a system of coplanar forces is in
equilibrium, then the algebraic sum of their
moments about any point in their plane is
zero.
(d) The algebraic sum of the moments of any two
forces about any point is equal to the moment
of the resultant about the same point
7. Which of the following is INCORRECT in the
laws of dry friction?
(a) The frictional force always acts in a direction
opposite to that in which the body tends to
move (b) The force of friction is dependent of the area
of contact between the two surfaces
(c) The magnitude of the limiting friction bears a
constant ratio to the normal reaction between
the two contacting surfaces
(d) The force of friction depends upon the
roughness/smoothness of the surfaces
8. A block weighing W = 20 kN is resting on an
inclined plane which makes and angle of 30ยบ to
the horizontal. The component of gravity force
parallel to inclined plane is-
(a) 17.32 kN
(b) 10 kN
(c) 5 kN
(d) 14.14 kN
9. The distance between the forces acting in the
couple is–
(a) Always a fixed distance
(b) A finite variable distance
(c) Zero
(d) Infinity
10. If no external torque acts on a rigid body, then
the product of its moment of inertia and the
angular velocity about the axis of rotation must
remain constant is the statement of-
(a) Law of parallelogram forces
(b) Law of polygon of forces
(c) Law of triangular forces
(d) Law of Conservation of Angular Momentum
11. Limiting force of friction is the :
(a) tangent of angle between normal-reaction and
the resultant of normal reaction and limiting friction.
(b) ratio of limiting friction and normal reaction
(c) the friction force acting when the body is just
about to move
(d) the friction force acting when the body is in
motion
12. The minimum angle made by an inclined plane
with the horizontal such that an object placed
on the inclined surface just begins to slide is
called-
(a) Angle of elevation
(b) Angle of friction
(c) Angle of Repose
(d) Angle of latitude
13. The angle between the resultant reaction and
normal to the plane on which the motion of
body is impending is known as–
(a) Angle of limiting friction
(b) Angle of repose
(c) Angle of friction
(d) Angle of zenith
14. The moment of inertia of a rectangular section
3 cm wide and 4 cm deep about X-X axis
passing through centre is-
(a) 9 cm4
(b) 12 cm4
(c) 16 cm4
(d) 20 cm
15. Mass moment of inertia has unit of _______
(a) kg-m2
(b) kg-m4
(c) kg/m2
(d) kg/m4
16. The product of area and square of distance of
centre of gravity of the area from that axis is
known as-
(a) Second moment of area
(b) Mass moment of inertia
(c) Second moment of mass
(d) First moment of area
17. What is the magnitude of the maximum
disturbance in the medium on either side of the
mean value called?
(a) Frequency
(b) Oscillation
(c) Amplitude
(d) Wavelength
18.In the case of perfect elastic collision, the
coefficient of restitution is :
(a) 1.0
(b) 0.5
(c) Less than 1.0
(d) Zero
19. A truss is said to be perfect when it satisfies the
following conditions:
(a) m = 2j + 3
(b) m = 3j – 2
(c) m = 2j – 3
(d) m = 3j + 2
20. A particle moves along a circular path with
constant speed. What is the nature of its
acceleration?
(a) its is zero
(b) It is Uniform
(c) Its direction changes
(d) its magnitude changes
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