Strength of Materials MCQ Questions and Answers in Civil Engineering

Question. Coefficient of friction is the
(a) Angle between normal reaction and the resultant of normal reaction and the 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

Answer : B

Question. The coefficient of friction depends on
(a) Area of contact
(b) Shape of surfaces
(c) Strength of surfaces
(d) Nature of surface

Answer : D

Question. Which of the following is not a vector quantity
(a) Weight
(b) Velocity
(c) Acceleration
(d) Force

Answer : A

Question. A force is completely defined when we specify
(a) Magnitude
(b) Direction
(c) Point of application
(d) All of the above

Answer : D

Question. The unit of force in S.I. units is
(a) Kilogram
(b) Newton
(c) Watt
(d) Dyne

Answer : B

Question. Center of percussion is
(a) The point of C.G.
(b) The point of metacentre
(c) The point of application of the resultant of all the forces tending to cause a body to rotate about a certain axis
(d) Point of suspension

Answer : C

Question. Which of the following is not a scalar quantity
(a) Mass
(b) Volume
(c) Density
(d) Acceleration

Answer : D

Question. The possible loading in various members of framed structures are
(a) Compression or tension
(b) Buckling or shear
(c) Shear or tension
(d) All of the above

Answer : A

Question. The angle which an inclined plane makes with the horizontal when a body placed on it is about to move down is known as angle of
(a) Friction
(b) Limiting friction
(c) Repose
(d) Kinematic friction

Answer : C

Question. Forces are called coplanar when all of them acting on body lie in
(a) One point
(b) One plane
(c) Different planes
(d) Perpendicular planes

Answer : B

Question. In the equation of virtual work, following force is neglected
(a) Reaction of any smooth surface with which the body is in contact
(b) Reaction of a rough surface of a body which rolls on it without slipping
(c) Reaction at a point or an axis, fixed in space, around which a body is con-strained to turn
(d) All of the above

Answer : D

Question. The center of gravity of a triangle lies at the point of
(a) Concurrence of the medians
(b) Intersection of its altitudes
(c) Intersection of bisector of angles
(d) Intersection of diagonals

Answer : A

Question. Pick up wrong statement about friction force for dry surfaces. Friction force is
(a) Proportional to normal load between the surfaces
(b) Dependent on the materials of contact surface
(c) Proportional to velocity of sliding
(d) Independent of the area of contact surfaces

Answer : C

Question. A number of forces acting at a point will be in equilibrium if
(a) Their total sum is zero
(b) Two resolved parts in two directions at right angles are equal
(c) Sum of resolved parts in any two perpendicular directions are both zero
(d) All of them are inclined equally

Answer : C

Question. D'Alembert's principle is used for
(a) Reducing the problem of kinetics to equivalent statics problem
(b) Determining stresses in the truss
(c) Stability of floating bodies
(d) Designing safe structures

Answer : A

Question. Coulomb friction is the friction between
(a) Bodies having relative motion
(b) Two dry surfaces
(c) Two lubricated surfaces
(d) Solids and liquids

Answer : A

Question. Frictional force encountered after commencement of motion is called
(a) Post friction
(b) Limiting friction
(c) Frictional resistance
(d) Dynamic friction

Answer : D

Question. If three forces acting in one plane upon a rigid body, keep it in equilibrium, then they must either
(a) Meet in a point
(b) Be all parallel
(c) At least two of them must meet
(d) All the above are correct

Answer : D

Question. Which of the following is not the unit of work, energy and heat?
(a) Kcal
(b) Kg m
(c) kW hr
(d) Hp

Answer : D

Question. When trying to turn a key into a lock, following is applied
(a) Coplanar force
(b) Non-coplanar forces
(c) Moment
(d) Couple

Answer : D

Question. Which of the following is not the unit of pressure?
(a) Kg/cm
(b) Atmosphere
(c) Mm of wcl
(d) Newton

Answer : D

Question. Two non-collinear parallel equal forces acting in opposite direction
(a) Balance each other
(b) Constitute a moment
(c) Constitute a couple 
(d) Constitute a moment of couple

Answer : C

Question. A flywheel on a motor goes from rest to 1000 rpm in 6 sec. The number of revolutions made is nearly equal to
(a) 25
(b) 50
(c) 100
(d) 250

Answer : B

Question. Which of the following is not the unit of energy
(a) Kg m
(b) Kcal
(c) Wattr
(d) Watt hours

Answer : C

Question. In ideal machines
(a) Mechanical advantage is greater than velocity ratio
(b) Mechanical advantage is equal to velocity ratio
(c) Mechanical advantage is less than velocity ratio
(d) Mechanical advantage is unity

Answer : B

Question. A heavy string attached at two ends at same horizontal level and when central dip is very small approaches the following curve
(a) Catenary
(b) Parabola
(c) Hyperbola
(d) Elliptical

Answer : B

Question. The unit of power in S.I. units is
(a) Newton meter
(b) Watt
(c) Joule
(d) Kilogram meter/sec

Answer : B

Question. If three forces acting in different planes can be represented by a triangle, these will be in
(a) Non-equilibrium
(b) Partial equilibrium
(c) Full equilibrium
(d) Unpredictable

Answer : A

Question. A body moves, from rest with a constant acceleration of 5 m per sec. The distance covered in 5 sec is most nearly
(a) 38 m
(b) 62.5 m
(c) 96 m
(d) 124 m

Answer : B

Question. Which is the correct statement about law of polygon of forces?
(a) If any number of forces acting at a point can be represented by the sides of a polygon taken in order, then the forces are in equilibrium
(b) 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 equilibrium
(c) If a polygon representing forces acting at a point is closed then forces are in equilibrium
(d) 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

Answer : D

Question. The M.I. of hollow circular section about a central axis perpendicular to section as compared to its M.I. about horizontal axis is
(a) Same
(b) Double
(c) Half
(d) Four times

Answer : B

Question. A body of weight W on inclined plane of a being pulled up by a horizontal force P will be on the point of motion up the plane when P is equal to
(a) W
(b) W sin (a + $)
(c) Wtan(a + <|))
(d) Wan(a-)

Answer : C

Question. According to principle of transmissibility of forces, the effect of a force upon a body is
(a) Maximum when it acts at the center of gravity of a body
(b) Different at different points in its line of action
(c) The same at every point in its line of action
(d) Minimum when it acts at the C.G. of the body

Answer : C

Question. Which of the following is the locus of a point that moves in such a manner that its distance from a fixed point is equal to its distance from a fixed line multiplied by a constant greater than one
(a) Ellipse
(b) Hyperbola
(c) Parabola
(d) Circle

Answer : B

Question. 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
(a) Forces
(b) Independence of forces
(c) Balance of force
(d) Resolution of forces

Answer : D

Question. If a number of forces act simultaneously on a particle, it is possible
(a) Not a replace them by a single force
(b) To replace them by a single force
(c) To replace them by a single force through C.G.
(d) To replace them by a couple

Answer : B

Question. In actual machines
(a) Mechanical advantage is greater than velocity ratio
(b) Mechanical advantage is equal to velocity ratio
(c) Mechanical advantage is less than velocity ratio
(d) Mechanical advantage is unity

Answer : C

Question. From a circular plate of diameter 6 cm is cut out a circle whose diameter is a radius of the plate. Find the e.g. of the remainder from the center of circular plate
(a) 0.5 cm
(b) 1.0 cm
(c) 1.5 cm
(d) 2.5 cm

Answer : A

Question. The center of gravity of a uniform lamina lies at
(a) The center of heavy portion
(b) The bottom surface
(c) The mid point of its axis
(d) All of the above

Answer : C

Question. If a rigid body is in equilibrium under the action of three forces, then
(a) These forces are equal
(b) The lines of action of these forces meet in a point
(c) The lines of action of these forces are parallel
(d) Both (B) and (C)

Answer : D

Question. Kinetic friction is the
(a) Tangent of angle between normal reaction and the resultant of normal reaction and the 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

Answer : D

Question. A sample of metal weighs 219 gms in air, 180 gms in water, 120 gms in an unknown fluid. Then which is correct statement about density of metal
(a) Density of metal can’t be determined
(b) Metal is twice as dense as water
(c) Metal will float in water
(d) Metal is twice as dense as unknown fluid

Answer : A

Question. The magnitude of two forces, which when acting at right angle produce resultant force of √10 kg and when acting at 60° produce resultant of √13 kg. These forces are
(a) 2 and √6kg
(b) 3 and 1 kg
(c) √5 and √5 kg
(d) 2 and 5 kg

Answer : C

Question. Angle of friction is the
(a) Angle between normal reaction and the resultant of normal reaction and the limiting friction
(b) Ratio of limiting friction and normal reaction
(c) The ratio of minimum friction force to the friction force acting when the body is just about to move
(d) The ratio of minimum friction force to friction force acting when the body is in motion

Answer : A

Question. A heavy ladder resting on floor and against a vertical wall may not be in equilibrium, if
(a) The floor is smooth and the wall is rough
(b) The floor is rough and the wall is smooth
(c) The floor and wall both are smooth surfaces
(d) The floor and wall both are rough surfaces

Answer : C

Question. A framed structure is perfect if it contains members equal to (where n = number of joints in a frame)
(a) 2n - 3
(b) n - 1
(c) 2n - 1
(d) n - 2

Answer : A

Question. A trolley wire weighs 1.2 kg per meter length. The ends of the wire are attached to two poles 20 meters apart. If the horizontal tension is 1500 kg find the dip in the middle of the span
(a) 2.5 cm
(b) 3.0 cm
(c) 4.0 cm
(d) 5.0 cm

Answer : C

Question. The centre of gravity (C.G.) of a solid hemisphere lies on the central radius
(a) At distance 3r/2 from the plane base
(b) At distance 3r/4 from the plane base
(c) At distance 3r/5 from the plane base
(d) At distance 3r/8 from the plane base

Answer : D

Question. Least force required to draw a body up the inclined plane is W sin (plane inclination + friction angle) applied in the direction
(a) Along the plane
(b) Horizontally
(c) Vertically
(d) At an angle equal to the angle of friction to the inclined plane

Answer : D

Question. A pair of smith’s tongs is an example of the lever of
(a) Zeioth order
(b) First order
(c) Second order
(d) Third order

Answer : C

Question. A force acting on a body may
(a) Introduce internal stresses
(b) Retard its motion
(c) Change its motion
(d) All of the above

Answer : D

Question. Forces are called concurrent when their lines of action meet in
(a) One point
(b) Two points
(c) Plane
(d) Perpendicular planes

Answer : A

Question. Which of the following is the example of lever of first order?
(a) Arm of man
(b) Pair of scissors
(c) Pair of clinical tongs
(d) All of the above

Answer : D

Question. In the lever of third order, load W, effort P and fulcrum F are oriented as follows
(a) W between P and F
(b) F between W and P
(c) P between W and F
(d) W, P and F all on one side

Answer : A

Question. The weight of a body is due to
(a) Centripetal force of earth
(b) Gravitational pull exerted by the earth
(c) Force of attraction experienced by par-ticles
(d) Gravitational force of attraction towards the centre of the earth

Answer : D

Question. The resultant of the following three couples 20 kg force, 0.5 m arm, +ve sense 30 kg force, 1 m arm, -ve sense 40 kg force, 0.25 m arm, +ve sense having arm of 0.5 m will be
(a) 20 kg, -ve sense
(b) 20 kg, +ve sense
(c) 10 kg, +ve sense
(d) 10 kg, -ve sense

Answer : A

Question. Which of the following is not the unit of power?
(a) kW (kilowatt)
(b) Hp (horse power)
(c) Kg m/sec
(d) Kcal/kg sec

Answer : D

Question. According to principle of moments
(a) If a system of coplanar forces is in equilibrium, then their algebraic sum is zero
(b) If a system of coplanar forces is in equilibrium, then the algebraic sum of their moments about any point in their plane is zero
(c) The algebraic sum of the moments of any two forces about any point is equal to moment of the resultant about the same point
(d) Positive and negative couples can be balanced

Answer : B

Question. Which of the following is a vector quantity
(a) Energy
(b) Mass
(c) Momentum
(d) Angle

Answer : C

Question. The product of either force of couple with the arm of the couple is called
(a) Resultant couple
(b) Moment of the forces
(c) Resulting couple
(d) Moment of the couple

Answer : D

Question. Two coplanar couples having equal and opposite moments
(a) Balance each other
(b) Produce a couple and an unbalanced force
(c) Are equivalent
(d) Produce a moment of couple

Answer : D

Question. If n = number of members andy = number of joints, then for a perfect frame, n =
(a) 2j-1
(b) 2j-2
(c) 2j-3
(d) 3j-2

Answer : C

Question. Which of the following is not the unit of distance?
(a) Angstrom
(b) Light year
(c) Millimeter
(d) Milestone

Answer : D

Question. Effect of a force on a body depends upon
(a) Magnitude
(b) Direction
(c) Position or line of action
(d) All of the above

Answer : D

Question. The C.G. of a plane lamina will not be at its geometrical centre in the case of a
(a) Right angled triangle
(b) Equilateral triangle
(c) Square
(d) Circle

Answer : A

Question. 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

Answer : C

Question. Tangent of angle of friction is equal to
(a) Kinetic friction
(b) Limiting friction
(c) Angle of repose
(d) Coefficient of friction

Answer : D

Question. In determining stresses in frames by methods of sections, the frame is divided into two parts by an imaginary section drawn in such a way as not to cut more than
(a) Two members with unknown forces of the frame
(b) Three members with unknown forces of the frame
(c) Four members with unknown forces of the frame
(d) Three members with known forces of the frame

Answer : B

Question. The unit of work or energy in S.I. units is
(a) Newton
(b) Pascal
(c) Watt
(d) Joule

Answer : D

Question. A cable with a uniformly distributed load per horizontal metre run will take the following shape
(a) Straight line
(b) Parabola
(c) Hyperbola
(d) Elliptical

Answer : B

Question. The algebraic sum of moments of the forces forming couple about any point in their plane is
(a) Equal to the moment of the couple
(b) Constant
(c) Both of above are correct
(d) Both of above are wrong

Answer : A