Dynamics of Machines solved MCQs

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1. Which of the following is incorrect regarding inertia force?

a. imaginary force

B. acts upon a rigid body

c. brings the body to equilibrium

d. same direction as of accelerating force

a. true

B. false

a. i. α/f

B. i. α/m.g

c. i/m.k

d. m.k/i

4. D-Alembert’s principle is used for which of the following?

a. change static problem into a dynamic problem

B. change dynamic problem to static problem

c. to calculate moment of inertia of rigid bodies

d. to calculate angular momentum of a system of masses

5. 2 D ALEMBERT'S PRINCIPLE - DYNAMIC ANALYSIS IN RECIPROCATING ENGINES

a. reversed effective force

B. net force

c. coriolis force

d. resultant force

6. Why the inertia torque acts in the opposite direction to the accelerating couple?

a. bring the body in equilibrium

B. to reduce the accelerating torque

c. acts as a constraint torque

d. increase the linear acceleration

7. A body remains in equilibrium if

a. inertia force is applied in the same direction to the resultant force

B. inertia force is applied in the direction opposite to the resultant force

c. inertia force is applied in the direction perpendicular to the resultant force

d. inertia force is applied in the direction parallel to the resultant force

a. true

B. false

a. i.α/f

B. i.α/m.g

c. i/m.k

d. m.k/i

10. Considering a four bar chain with each link having linear and angular acceleration, applying D-Alembert’s principle will never result in which of the following member?

a. 2- force member

B. 3- force member

c. 4 – force member

d. non accelerating member

11. The net force acting on the crosshead pin is known as

a. crank pin effort

B. crank effort

c. piston effort

d. shaft effort

a. true

B. false

a. tdc to bdc

B. bdc to tdc

c. midway to tdc

d. bdc to midway

a. tdc to bdc

B. bdc to tdc

c. midway to tdc

d. bdc to midway

15. When the piston is accelerated, the piston effort is given by which of the following the equation?

a. f(l) – f(i)

B. f(l) + f(i)

c. f(l) ± f(i)

d. f(l) – f(i) + r(f)

16. In the presence of frictional resistance, the expression for piston effort is

a. f(l) – f(i)

B. f(l) + f(i)

c. f(l) ± f(i) – r(f)

d. f(l) – f(i) + r(f)

17. Crank effort is the product of crank pin radius and

a. thrust on sides

B. crankpin effort

c. force acting along connecting rod

d. piston effort

a. true

B. false

a. 17.56 n

B. 19.2 n

c. 18.53 n

d. 18.00 n

a. 88000 n

B. 90560 n

c. 78036 n

d. 88357 n

21. 2 m and the cylinder bore is 0.5 m. engine runs at 250 r.p.m & 30° from T.D.C. Find the piston effort.

a. 32.4 kn

B. 35.2 kn

c. 37.3 kn d) 40.2 n

a. true

B. false

23. For a multicylinder engine, the coefficient of fluctuation of speed would vary with

a. number of cylinders

B. remains unaffected

c. length of connecting rod

d. input temperature

a. 0.5

B. 1.5

c. 2

d. 0.66

a. the gases

B. on the gases

c. piston wall

d. valve