   ## Applied Mechanics MCQ Practice Questions (Civil Engineering) Set 7

Options are :

• 60°
• 57°
• 59°
• 58°

Options are :

• B
• A
• D
• C

##### To avoid bending action at the base of a pier:

Options are :

• Suspension cable and anchor cables are attached to a saddle mounted on rollers on top of the pier
• Suspension and anchor cables are kept at the same level
• None the these
• Suspension and anchor cables are fixed to pier top

Answer :Suspension and anchor cables are fixed to pier top

##### A Second's pendulum gains 2 minutes a day. To make it to keep correct time its length:

Options are :

• Is not changed but weight of the bob is decreased
• Must be decreased
• Is not changed but weight of the bob is increased
• Must be increased
• None of these

Options are :

• m^(3)
• kg/m^(2)
• m^(4)
• kg-m^(2)
• kg/m

Options are :

• B
• A
• D
• C

Options are :

• 110 kg
• 105.5 kg
• 108.5 kg
• 102.5 kg

Options are :

• 19.5 kg
• 17.5 kg
• 22.5 kg
• 25 kg

##### The resolved part of the resultant of two forces inclined at an angle ? in a given direction is:

Options are :

• Algebraic sum of the resolved parts of the forces in the direction
• Sum of the forces multiplied by the sine ?
• Arithmetical sum of the resolved parts of the forces in the direction
• Sum of the forces multiplied by the tangent ?°
• Difference of the forces multiplied by cosine ?°

Answer :Algebraic sum of the resolved parts of the forces in the direction

Options are :

• 10 sec
• 15 sec
• 40 sec
• 30 sec
• 20 sec

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

Options are :

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

Answer :The force of friction always acts in a direction opposite to that in which the body tends to move

Options are :

• 10 Newtons
• 12 Newtons
• 8 Newtons
• 5 Newtons

Options are :

• Parabolic
• Circular
• Catenary
• Elliptical

##### Lami's theroem states that:

Options are :

• Three forces acting at a point are always in equilibrium
• 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
• None of these
• 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
• 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

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

Options are :

• 3 sec
• 4 sec
• 5 sec
• 1 sec
• 2 sec

##### The resultant of the forces acting on a body will be zero if the body:

Options are :

• Moves with variable velocity in a straight line
• Rotates
• Moves along a curved path
• Does not move at all

Answer :Does not move at all

##### A body is said to move with Simple Harmonic Motion if its acceleration, is:

Options are :

• Proportional to the distance from the point of reference and directed towards it
• Inversely proportion to the distance from the point of reference
• None of these
• Proportional to the square of the distance from the point of reference
• Always directed away from the centre, the point of reference

Answer :Proportional to the distance from the point of reference and directed towards it

##### The following statement is one of the laws of Dynamic friction:

Options are :

• 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
• For moderate speeds the force of friction remains constant but decreases slightly with the increase of speed
• All the above
• The force of friction always acts in a direction opposite to that in which a body is moving

##### According to Law of Triangle of Forces:

Options are :

• If three forces acting at a point are in equilibrium each force is proportional to the sine of the angle between the other two
• Three forces acting at a point, can be rep-resented by the sides of a triangle, each side being in proportion to the force
• Three forces acting along the sides of a triangle are always in equilibrium
• If three forces acting on a, point can be represented.in magnitude and direction, by the sides of a triangle taken in order, these will be in equilibrium
• If the forces acting on a particle be represented in magnitude and direction by the two sides of a triangle taken in order, their resultant will be represented in magnitude and direction by the third side of the triangle, taken in opposite order

Answer :If the forces acting on a particle be represented in magnitude and direction by the two sides of a triangle taken in order, their resultant will be represented in magnitude and direction by the third side of the triangle, taken in opposite order

##### Pick up the correct statement from the following for the structure shown in below figure. Larger image Options are :

• The horizontal reaction at C is 2?3t ?
• The horizontal reaction at A is 2?3t ?
• The vertical reaction at A is zero
• The vertical reaction at C is 2 t ?
• All the above

##### Power can be expressed as:

Options are :

• Work/energy
• Work/time
• Work x time
• Work/distance

Options are :

• D
• C
• B
• A

##### 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:

Options are :

• Zero work
• Imaginary work
• Virtual work
• Negative work

##### The velocity of a moving body, is:

Options are :

• A vector quantity
• None of these
• A scalar quantity
• A scalar as well as a vector quantity

##### If two forces acting at a point are in equilibrium, they must be equal in magnitude and their line of action must be along:

Options are :

• None of these
• The same line in opposite sense
• The perpendicular to both the lines
• The same line in the same sense

Answer :The same line in opposite sense

Options are :

• 70 m/sec
• 80 m/sec
• 85 m/sec
• 75 m/sec
• 90 m/sec

Options are :

• D
• A
• C
• B

##### A particle executes a simple harmonic motion. While passing through the mean position, the particle possesses:

Options are :

• Minimum kinetic, energy and minimum potential energy
• Maximum kinetic energy and maximum potential energy
• Minimum kinetic energy and maximum potential energy
• Maximum kinetic energy and minimum potential energy
• None of these

Answer :Maximum kinetic energy and minimum potential energy

Options are :

• 45°
• 90°
• 60°
• 30°

##### According to Kennedy's theorem, if three bodies have plane motions, their instantaneous centres lie on:

Options are :

• A point
• Two straight lines
• A straight line
• A triangle