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This set of Mechatronics Multiple Choice Questions & Answers (MCQs) focuses on Mechatronics Set 3
Q1 | Compression stroke results in
- formation of negative loop
- formation of positive loop
- formation of an infinite loop
- formation of no loop
Q2 | 4 strokes engine have a lower thermal efficiency than 2 stroke engine.
- true
- false
Q3 | 3 BALANCING MACHINES-FIELD BALANCING OF DISCS AND ROTORS.
- centripetal forces
- centrifugal forces
- friction forces
- inertia forces
Q4 | Balancing of single rotating mass by balancing masses in same plane and in different planes cannot take place.
- true
- false
Q5 | 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
Q6 | 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
Q7 | If the unbalanced system is not set right then.
- static forces develop
- dynamic forces develop
- tangential forces develop
- radial forces develop
Q8 | What is not the effect of unbalanced forces?
- load on bearings
- dangerous vibrations
- stresses in various members
- violation of conservation of mass principle
Q9 | 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
Q10 | 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
Q11 | The accelerometer is used as a transducer to measure earthquake in Richter scale. Its design is based on the principle that
- its natural frequency is very low in comparison to the frequency of vibration
- its natural frequency is very high in comparison to the frequency of vibration
- its natural frequency is equal to the frequency of vibration
- measurement of vibratory motion is without any reference point
Q12 | Critical speed is expressed as
- rotation of shaft in degrees
- rotation of shaft in radians
- rotation of shaft in minutes
- natural frequency of the shaft
Q13 | The first critical speed of an automobile running on a sinusoidal road is calculated by (modeling it as a single degree of freedom system)
- resonance
- approximation
- superposition
- rayleigh quotient
Q14 | The natural frequency of a spring-mass system on earth is ωn. The natural frequency of this system on the moon (gmoon = gearth/6) is
- ωn
- 0.408ωn
- 0.204ωn
- 0.167ωn
Q15 | 6 kN/m and the damping constant of the damper is 400 Ns/m. If the mass is 50 kg, then the damping factor (d ) and damped natural frequency (fn), respectively, are
- 0.471 and 1.19 hz
- 0.471 and 7.48 hz
- 0.666 and 1.35 hz
- 0.666 and 8.50 hz
Q16 | 5 m/s.
- 4.19
- 5
- 3.49
- 3.36
Q17 | Which of the following expression represent the angular acceleration α of the connecting rod?
- −ω2 . sin θ/n
- −ω2 . cos θ.n
- ω2. cos θ/n
- ω2 . sin θ.n
Q18 | While calculating angular acceleration of the connecting rod, sin2(θ) term is neglected.
- true
- false
Q19 | In a slider crank mechanism, the length of the crank and connecting rod are 180 mm and 540 mm respectively. The crank position is 45° from inner dead centre. The crank shaft speed is 450 r.p.m. (clockwise), calculate angular velocity of the connecting rod in rad/s.
- 10.3
- 11.1
- 12.2
- 11.8
Q20 | When a body is subjected to transverse vibrations, the stress induced in a body will be
- shear stress
- bending stress
- tensile stress
- compressive stress
Q21 | Longitudinal vibrations are said to occur when the particles of a body moves
- perpendicular to its axis
- parallel to its axis
- in a circle about its axis
- none of the mentioned
Q22 | When a body is subjected to transverse vibrations, the stress induced in a body will be
- shear stress
- tensile stress
- compressive stress
- none of the mentioned
Q23 | The factor which affects the critical speed of a shaft is
- diameter of the disc
- span of the shaft
- eccentricity
- all of the mentioned
Q24 | The ratio of the maximum displacement of the forced vibration to the deflection due to the static force, is known as
- damping factor
- damping coefficient
- logarithmic decrement
- magnification factor
Q25 | Which of the following systems produce a vibration in the foundation?
- unbalanced machine
- balanced machine
- coupled machine
- uncoupled machine