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This set of Dynamics of Machines Multiple Choice Questions & Answers (MCQs) focuses on Dynamics Of Machines Set 3
Q1 | Which of the following statements is correct about the balancing of a mechanical system?
- if it is under static balance, then there will be dynamic balance also
- if it is under dynamic balance, then there will be static balance also
- both static as well as dynamic balance have to be achieved separately
- none of the mentioned
Q2 | In a locomotive, the ratio of the connecting rod length to the crank radius is kept very large in order to
- minimize the effect of primary forces
- minimize the effect of secondary forces
- have perfect balancing
- start the locomotive conveniently
Q3 | In case of partial balancing of locomotives, the maximum magnitude of the unbalanced force perpendicular to the line of stroke is called hammer blow and this has to be limited by proper choice of the balancing mass and its radial position.
- true
- false
Q4 | Multi-cylinder engines are desirable because
- only balancing problems are reduced
- only flywheel size is reduced
- both (a) and (b)
- none of the mentioned
Q5 | Secondary forces in reciprocating mass on engine frame are
- of same frequency as of primary forces
- twice the frequency as of primary forces
- four times the frequency as of primary forces
- none of the mentioned
Q6 | Which of the following process is not the part of working of a 4 stroke I.C Engine?
- compression
- suction
- exhaust
- turbine flow
Q7 | 4-stroke engine has one power stroke per 2 revolutions hence turning moment diagram is uniform.
- true
- false
Q8 | Work produced by the 4-stroke engine is less because
- one power stroke per 2 revolutions
- one power stroke per revolution
- one power stroke per 4 revolution
- four power stroke per revolution
Q9 | A negative loop is formed in the turning moment diagram because the pressure inside the cylinder is than the atmospheric pressure.
- equal
- more
- less
- no pressure inside
Q10 | When the work is by on the gases, which of the following effect is observed on the turning moment diagram?
- formation of negative loop
- formation of positive loop
- formation of an infinite loop
- formation of no loop
Q11 | Compression stroke results in
- formation of negative loop
- formation of positive loop
- formation of an infinite loop
- formation of no loop
Q12 | 4 strokes engine have a lower thermal efficiency than 2 stroke engine.
- true
- false
Q13 | While drawing the turning moment diagram, which of the forces in not taken into account?
- inertia force
- force on connecting rod
- force on crank
- coriolis force
Q14 | In the given turning moment diagram, the process X is known as
- suction
- compression
- power
- exhaust
Q15 | 3 BALANCING MACHINES-FIELD BALANCING OF DISCS AND ROTORS.
- centripetal forces
- centrifugal forces
- friction forces
- inertia forces
Q16 | Balancing of single rotating mass by balancing masses in same plane and in different planes cannot take place.
- true
- false
Q17 | Which of the following is true for centrifugal force causing unbalance?
- direction changes with rotation
- magnitude changes with rotation
- direction and magnitude both change with rotation
- direction and magnitude both remain unchanged with rotation
Q18 | In a revolving rotor, the centrifugal force remains balanced as long as the centre of the mass of the rotor lies
- below the axis of shaft
- on the axis of the shaft
- above the axis of shaft
- away from the axis of shaft
Q19 | If the unbalanced system is not set right then.
- static forces develop
- dynamic forces develop
- tangential forces develop
- radial forces develop
Q20 | What is not the effect of unbalanced forces?
- load on bearings
- dangerous vibrations
- stresses in various members
- violation of conservation of mass principle
Q21 | What is the effect of a rotating mass of a shaft on a system?
- bend the shaft
- twist the shaft
- extend the shaft
- compress the shaft
Q22 | Balancing of reciprocating masses is the process of providing the second mass in order to counteract the effect of the centrifugal force of the first mass.
- true
- false
Q23 | The critical speed of a shaft with a disc supported in between is equal to the natural frequency of the system in
- transverse vibrations
- torsional vibrations
- longitudinal vibrations
- none of the mentioned
Q24 | When there is a reduction in amplitude over every cycle of vibration, then the body is said to have
- free vibration
- forced vibration
- damped vibration
- under damped vibration
Q25 | In vibration isolation system, if ω/ωn < 2, then for all values of damping factor, the transmissibility will be
- less than unity
- equal to unity
- greater than unity
- zero