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EndsemNov 20242019 patternBE Mech

Dynamics of Machinery SPPU Endsem Question Paper Nov 2024

All 8 questions from this SPPU endsem paper, as printed. Read them here or open the PDF.

Open the PDFMost repeated Dynamics of Machinery questions
Subject code
402042
Pattern
2019 pattern
Exam
Endsem
Session
Nov 2024
Max. marks
70
Time
2½ Hours
Semester
VII
Paper code
[6354]-613

Printed for: B.E. (Mehanical Engineering)

Instructions to the candidates

  1. Answer Q.1 or Q.2, Q.3 or Q.4,Q.5 or Q.6 Q.7, or Q.8.
  2. Neat diagrams must be drawn wherever necessary.
  3. Use of logarithmic tables, slide rule, and electronic pocket calculator is allowed.
  4. Figures to the right indicate full marks.
  5. Assume suitable data, if necessary.

Questions

  1. Q1

    1. a)

      Find the natural frequency of the system as shown in figure.1 using Energy Method or Newton’s Approach.

      [8]
    2. b)

      Explain with a neat diagram mathematical model of a Bicycle.

      [5]
    3. c)

      Explain the following terms used in vibration. i) Free Vibrations ii) Forced Vibrations

      [4]

  2. Q2

    1. a)

      This part has equations that don’t show as text. Open the PDF to read it.

      [8]
    2. b)

      Discuss over-damped, under-damped and critically damped system with the help of amplitude versus time plot.

      [5]
    3. c)

      Define the following terms i) Viscous damping ii) Coulomb damping Figure. 1 2

      [4]

  3. Q3

    1. a)

      A system having rotating unbalance has a total mass of 25 kg. The unbalanced mass of 1 kg rotates with a radius of 0.04m It has been observed that at a speed of 1000 rpm, the system & eccentric mass has a phase difference of 90 degrees and corresponding amplitude is 0.015 m. Find out i) natural frequency of the system ii) damping factor iii) amplitude at 1500 rpm iv) Phase angle at 1500 rpm.

      [8]
    2. b)

      Explain frequency response curves (Magnification factor Vs. Frequency ratio) forced vibration due to external harmonic excitation.

      [5]
    3. c)

      Define Quality factor and state its significance in frequency response curves.

      Also asked:Nov 2022

      [5]

  4. Q4

    1. a)

      The springs of an automobile trailer are compressed 0.1m under its own weight. Find the critical speed when the trailer is passing over a road with a profile of sine-wave whose amplitude is 80 mm and the wavelength is 14 m. Find the amplitude of vibration at a speed of 60 km/hr.

      Also asked:May 2024

      [8]
    2. b)

      What is critical speed of rotor without damping? Explain with the neat sketch.

      [5]
    3. c)

      Explain Force transmissibility on the basis of i) Definition ii) Equation iii) Terminology used in equation 3

      [5]

  5. Q5

    1. a)

      This part has equations that don’t show as text. Open the PDF to read it.

      [10]
    2. b)

      Derive the equation for the length of Torsionally Equivalent Shaft.

      Also asked:Nov 2025 ·May 2025 ·May 2024 ·Nov 2023 ·May 2023 ·Nov 2022

      [8]

  6. Q6

    1. a)

      Determine the natural frequencies and position of node of torsional vibration system having two rotors A and B attached to the ends of a shaft 1500 mm long. The MOI of rotor A is 650 kgm 2 and that of rotor B is 215 kgm 2 . The shaft is 95 mm diameter for the first 600 mm, 60 mm diameter for the next 500 mm lenth and 50 mm diameter for the remaining length. Modulus of rigidity of shaft is 0.8 x 10 5 Mpa. (Assume value of equivalent diameter as 0.1 m).

      [10]
    2. b)

      Explain free vibrations of a two rotor system using following parameters. i) Zero frequency ii) Node point iii) Position of node iv) Amplitude ratios of two rotors Figure. 2 4

      [8]

  7. Q7

    1. a)

      Differentiate Time domain and frequency domain Analysis. Explain how frequency spectrum can be used to detect vibration related faults in a system.

      Also asked:May 2024 ·Nov 2022

      [8]
    2. b)

      Explain any one frequency measuring instrument with a neat diagram.

      Also asked:Nov 2025 ·Nov 2022

      [5]
    3. c)

      Classify vibration measuring instruments.

      Also asked:Nov 2025 ·Nov 2022

      [4]

  8. Q8

    1. a)

      Show that as a distance from a point source doubles, the Sound Intensity Level decreases by 6 dB. Assume that sound propagates in the form of spherical waves.

      [8]
    2. b)

      Write a short note on Sound fields.

      [5]
    3. c)

      This part has equations that don’t show as text. Open the PDF to read it.

      [4]