# Applied Mechanics MCQ Civil Engineering

50 Questions 30 Mins

Following are some of the multiple choice questions on the Applied Mechanics with answers that will help the students in developing their knowledge.

## Applied Mechanics MCQ

• 0.25 cm
• 0.50 cm
• 0.75 cm
• 1.00 cm

### 2. The following is not a law of static friction:

• The force of friction always acts in a direction opposite to that in which the body tends to move
• The force of friction is dependent upon the area of contact
• The force of friction depends upon the roughness of the surface
• The magnitude of the limiting friction bears a constant ratio to the normal reaction between two surfaces

• ⅔ Mr²
• ½ Mr²
• Mr²
• πr4/2

• 20 kg
• 25 kg
• 30 kg
• 35 kg

• Zero
• 30 m
• 50 m
• 60 m

### 6. When a circular wheel rolls on a straight track, then the shape of body centrode and space centrode respectively are

• Straight line and parabola
• Straight line and circle
• Circle and straight line
• Circle and parabola

### 7. A cable loaded with 10 kN/m of span is stretched between supports in the same horizontal line 100 m apart. If the central dip is 10 m, then the maximum and minimum pull in the cable respectively are

• 1346.3 kN and 1500 kN
• 1436.2 kN and 1250 kN
• 1346.3 kN and 1250 kN
• 1436.2 kN and 1500 kN

### 8. Time period and length of a second’s pendulum respectively are

• 1 sec and 99.4 cm
• 1 sec and 92.7 cm
• 2 sec and 99.4 cm
• 2 sec and 92.7 cm

• 0° and 90°
• 180° and 90°
• 90° and 180°
• 180° and 0°

• 2 J
• 4 J
• 6 J
• 8 J

### 11. A sphere is resting on two planes BA and BC which are inclined at 45° and 60° respectively with the horizontal. The reaction on the plane BA will be

• Less than that on BC
• More than that of BC
• Equal to that on BC
• None of these

• 1.5
• 5
• 25
• 314

### 13. If ‘α’ is the angular acceleration of a compound pendulum whose angular displacement is ‘θ’, the frequency of the motion is

• 2π √(α/θ)
• (1/2π) √(α/θ)
• 4π √(α/θ)
• 2π √(α - θ)

### 14. For the given values of initial velocity of projection and angle of inclination of the plane, the maximum range for a projectile projected upwards will be obtained, if the angle of projection is

• α = π/4 - β/2
• α = π/2 + β/2
• α = β/2 - π/2
• α = π/4 - β/2

• 30°
• 45°
• 90°

### 16. On a ladder resisting on a smooth ground and leaning against a rough vertical wall, the force of friction acts

• Towards the wall at its upper end
• Away from the wall at its upper end
• Upwards at its upper end
• Downwards at its upper end

### 17. On a ladder resting on a rough ground and leaning against a smooth vertical wall, the force of friction acts

• Downwards at its upper end
• Upwards at its upper end
• Perpendicular to the wall at its upper end
• Zero at its upper end

• 10³ dynes
• 10⁴ dynes
• 10⁵ dynes
• 10⁶ dynes

• gra/h
• √(gra/h)
• ∛(gra/h)
• 4√(gra/h)

### 20. The masses of two balls are in the ratio of 2 : 1 and their respective velocities are in the ratio of 1 : 2 but in opposite direction before impact. If the coefficient of restitution is ½, the velocities of separation of the balls will be equal to

• Original velocity in the same direction
• Half the original velocity in the same direction
• Half the original velocity in the opposite direction
• Original velocity in the opposite direction

### 21. If two forces of 3 kg and 4 kg act at right angles to each other, their resultant force will be equal to

• 7 kg
• 1 kg
• 5 kg
• None of these

### 22. Pick up the correct statement from the following. A rubber ball when strikes a wall rebounds but a lead ball of same mass and velocity when strikes the same wall, falls down

• Rubber and lead balls undergo equal changes in momentum
• Change in momentum suffered by lead ball is less that of rubber ball
• Momentum of rubber ball is less than that of lead ball
• None of these

### 23. The centre of gravity of a trapezoidal dam section whose top width is a, bottom width is band the vertical side is a, from its vertical face is

• (a² + ab + b²)/3 (a + b)
• (b² + bc + c²)/3 (b + c)
• (a² + ab + c²)/3 (a + c)
• None of these

### 25. A body of weight ‘w’ placed on an inclined plane is acted upon by a force ‘P’ parallel to the plane which causes the body just to move up the plane. If the angle of inclination of the plane is ‘θ’ and angle of friction is ‘φ’, the minimum value of ‘P’, is

• w sin (φ - θ)/cos φ
• w sin (θ - φ)/cos φ
• w cos (θ + φ)/cos φ
• w sinθ cos(θ - φ)/sin φ

• 40 g
• 60 g
• 80 g
• 100 g

### 27. The unit of force in C.G.S. system of units, is called

• Dyne
• Newton
• Kg
• All the above

• kg.m
• kg/m2
• kg/sec2
• kg/sec

• 5 sec
• 8 sec
• 10 sec
• 20 sec

### 30. If a particle moves with a uniform angular velocity ‘ω’ radians/sec along the circumference of a circle of radius ‘r’, the equation for the velocity of the particle, is

• v = ω √(y² - r²)
• y = ω √(y - r)
• v = ω √(r² + y²)
• v = ω √(r² - y²)

### 31. Periodic time of a particle moving with simple harmonic motion is the time taken by the particle for

• Half oscillation
• Quarter oscillation
• Complete oscillation
• None of these

### 32. Two objects moving with uniform speeds are 5 m apart after 1 second when they move towards each other and are 1 m apart when they move in the same direction.The speeds of the objects are:

• 2 m/sec and 2 m/sec
• 3 m/sec and 2 m/sec
• 3 m/sec and 3 m/sec
• 4 m/sec and 6 m/sec

• 0.01 m/sec
• 0.05 m/sec
• 1.00 m/sec
• 1.5 m/see

### 34. A satellite goes on moving along its orbit round the earth due to

• Gravitational force
• Centrifugal force
• Centripetal force
• None of these

### 35. A satellite moves in its orbit around the earth due to

• Gravitational force
• Centripetal force
• Centrifugal force
• None of these

### 36. In SI units, the units of force and energy are respectively

• Newton and watt
• Dyne and erg
• Newton and joule
• kg wt and joule

• M-1L2r2
• M-1L3r2
• M-2L3T2
• M1L3T2

### 38. The motion of a bicycle wheel is

• Translatory
• Rotary
• Rotary and translatory
• Curvilinear

• ED
• DC
• BC
• BD

• 1 t
• 2 t
• 3 t
• 3.5 t

• g1
• g2
• g1/g2
• g2/g1

• 0.2 R
• 0.4 R
• 0.3 R
• 0.6 R

### 44. The centre of gravity of the trapezium as shown in below figure from the side is at a distance of

• (h/3) × [(b + 2a)/(b + a)]
• (h/3) × [(2b + a)/(b + a)]
• (h/2) × [(b + 2a)/(b + a)]
• (h/2) × [(2b + a)/(b + a)]

### 45. Effect of a force on a body depends upon its

• Direction
• Magnitude
• Position
• All the above

• 50 and 75
• 75 and 50
• 75 and 75
• 50 and 50

• 0.25
• 0.50
• 0.75
• 1.0

• 0.33
• 0.44
• 0.57
• 0.67

### 49. Parallelogram Law of Forces states, "if two forces acting simultaneously on a particle be represented in magnitude and direction by two adjacent sides of a parallelogram, their resultant may be represented in magnitude and direction by

• Its longer side
• Its shorter side
• The diagonal of the parallelogram which does not pass through the point of intersection of the forces
• The diagonal of the parallelogram which passes through the point of intersection of the forces

### 50. The resultant of two forces ‘P’ and ‘Q’ acting at an angle ‘θ’, is

• P² + Q² + 2P sin θ
• P² + Q² + 2PQ cos θ
• P² + Q² + 2PQ tan θ
• √(P² + Q² + 2PQ cos θ)