# Applied Mechanics 1

Objective Questions and Answers of Civil Engineering: Applied Mechanics 1

Subject: Applied Mechanics 1

Part 1: Objective questions and answers of Applied Mechanics

Q1. The condition of equilibrium for any system of forces in a plane is

a) That polygon of forces must close

b) That resultant couple must be zero

c) Both (a) and (b)

d) None of the above

Q2. A rigid body is in a stable equilibrium if the application of any force

a) Can raise the cg of the body but cannot lower it

b) Tends to lower the cg of the body

c) Neither raises nor lowers the cg of the body

d) None of above

Q3. A block in the shape of a parallelopiped of sides lm x 2mx 3m lies on the surface. Which of the faces gives maximum stable block?

a) 1 m x 2 m

b) 2 m x 3 m

c) 1 m x 3m

d) Equally stable on all faces

Q4. If the resultant of two forces has the same magnitude as either of the force, then the angle between the two forces is

a) 30°

b) 45°

c) 60°

d) 120°

Q5. The angles between two forces to make their resultant a minimum and a maximum respectively are

a) 0° and 90°

b) 180° and 90°

c) 90° and 180°

d) 180° and 0°

Q6. A funicular polygon cannot be made to pass through

a) One specified point

b) Two specified points

c) Three specified points

d) More than three specified points

Q7. For a non-concurrent force system to be in equilibrium

a) Only the closure of force polygon is sufficient

b) Only the closure of funicular polygon is sufficient

c) Both force polygon and funicular polygon must close

d) None of the above

Q8. If a set of given forces are such that their free vectors build a closed polygon, then

a) The resultant force and resultant couple are always zero

b) The resultant force is zero but resultant couple is not zero

c) The resultant force is zero but resultant couple may not be zero

d) The resultant force and resultant couple both may not be zero

Q9. The member forces in a statically in determinate truss

a) Can be obtained by graphic statics

b) Cannot be obtained by graphic statics

c) May be obtained by graphic statics

d) Can be obtained by graphic statics by trial and error

Q10. The pole distance is measured in

a) Distance scale

b) Force scale

c) Mass scale

d) Time scale

Q11. Two circular discs of same weight and thickness are made from metals having different densities. Which disc will have the larger rotational inertia about its central axis?

a) Disc with larger density

b) Disc with smaller density

c) Both discs will have same rotational inertia

d) None of the above

Q12. A symmetrical body is rotating about its axis of symmetry, its moment of inertia about the axis of rotation being 2 kg –m^2 and its rate of rotation 2 revolutions/see. The angular momentum of the body in kg-m^2/sec is

a) 4

b) 6 7i

c) 8tc

d) 8

Q13. The torque produced by a force depends on

i. The magnitude of the force

ii. The direction of the force

iii. The point of application of the force relative to origin the correct answer is

a) Only (i)

b) Both (i) and (ii)

c) Both (i) and (iii)

d) All (i), (ii) and (iii)

Q14. A solid cylinder of mass m and radius r rolls down an inclined plane without slipping. The acceleration of center of mass of rolling cylinder is

a) (1/3) g sinb

b) (2/3) g cos 9

c) (2/3) g sin 0

d) G sin 9

Where ‘g’ is acceleration due to gravity and 0 is inclination of plane with horizontal.

Q15. A sphere and a cylinder having the same mass and radii start from rest and roll down the same inclined plane. Which body gets to the bottom first?

a) Sphere with greater rotational energy at bottom than cylinder

b) Sphere with lesser rotational energy at bottom than cylinder

c) Cylinder with greater rotational energy at bottom than sphere

d) Both reach the bottom simultaneously with equal rotational energy At bottom

Q16. A cylinder will slip on an inclined plane of inclination 0 if the coefficient of static friction between plane and cylinder is

a) Less than (1/3) tan 0

b) Less than (2/3) tan 0

c) Less than (1/3) sin 6

d) Less than (2/3) sin 6

Q17. If the angular distance, 0 = 2t3 – 3t2, the angular acceleration at t = 1 sec. Is

Q18. A particle moves in a straight line and its position is defined by the equation x = 6 t2 – t3 where t is expressed in seconds and x in meters. The maximum velocity during the motion is

a) 6 m/sec

b) 12 m/sec

c) 24 m/sec

d) 48 m/sec

Q19. A disc of mass 4 kg, radius 0.5m and moment of inertia 3 kg-m2 rolls on a horizontal surface so that its center moves with speed 5 m/see. Kinetic energy of the disc is

a) 50 j

b) 150 j

c) 200 j

d) 400 j

Q20. Select the correct statement

a) The body centrode rolls on the space centrode.

b) The space centrode rolls on the body centrode.

c) Both body and space centrodes may role on each other.

d) The body centrode never touches space centrode.

Part 1: Objective questions and answers of Applied Mechanics