Maharashtra State Board of Technical Education 2008 Diploma Mechanical Engineering (measurements and control ) - Question Paper

Sample ques. Paper - I
Course Name : Mechanical Engineering and Production Engineering/ Technology
Course Code : ME/PT/PG/MH/MI
Semester : Fifth
Subject : Measurement & Control
Marks : 80 Time : three hrs.

Instructions:
1. All ques. are compulsory.
2. Illustrate your answers with neat sketches wherever necessary.
3. Figures to the right indicate full marks.
4. presume suitable data if necessary.
5. Preferably, write the answers in sequential order.

Q1. Attempt Any 4 the subsequent. four x four = 16
a) Distinguish ranging from span and range of an instrument with the improper examples.
b) List various measurement and control systems used in air conditioner. discuss any one
with neat sketch.
c) What is the significance of subsequent characteristics of measuring instruments on its
performance.1) Threshold & Resolution 2) Measuring lag
d) i) A Stroboscope projects 5000 flashes per min on a disc mounted on the shaft of a
machine. obtain the speed of the machine if the disc appears stationary & has a single
image of five points. Also compute the fault.
ii) What would be the 2 possible shaft speeds if the five points appears to be revolving once
in 12 seconds?
e) i) describe fault in measurement.
ii) Draw the block diagram of close loop system and discuss.
f) discuss the characteristics of LVDT with neat sketch.

Q 2. Attempt any 3 of the subsequent. 4x3 = 12
a) i) discuss Overshoot phenomenon in instrument.
9096
ii) When a step input of 10 KN/mm2 is applied to the pressure gauge the pointer swings to
pressure 10.25 KN/mm2 & finally comes to rest at 10.13 KN/mm2. Determine the
overshoot of the gauge studying and express it as percentage of final studying. Also
compute % fault of the gauge.
b) Illustrate with suitable sketch proportional mode of control.
c) discuss with neat sketch drag cup tachometer. State its applications.
d) Distinguish ranging from hydraulic, Pneumatic and electronic control system based on the
subsequent points.
1) Capacity 2) Accuracy of control 3) cost 4) Applications

Q3. Attempt any 3 of the subsequent. four x three = 12
a) i) discuss why piezo-electric transducers are used for the measurement of dynamic volume
only.
ii) provide a few examples of mechanical transducer where there is transduction from force to
displacement.
b) discuss with neat sketch slipping clutch tachometer.
c) List control devices with which you are familiar and discuss 1 of them in brief.
d) i) state the factors to be considered while selecting the transducer.
ii) A metallic toothed rotor having 60 teeth is mounted on shaft whose speed is to be
determined. The pulses induced in the inductive kind magnetic pick up were registered to
be 3600 per second, estimate the shaft speed.

Q4. Attempt any 4 of the subsequent. four x four = 16
a) discuss laws of thermocouples with neat sketches.
b) Classify temperature measuring instruments, and indicate approximate temp. range of every
category.
c) What is the value of resistance R2 at initial balance with zero strain? When the whetstone’s
bridge was balanced after the strain was applied this resistance increased to 9997
. Make
computation for change in resistance of the gauge and the strain applied if the Gauge factor is
2.0 provided – R1 = 100
, R2= Variable, R3 = 100
, R4 = 10000

d) discuss the various sources of errors in measurement & Measuring instrument.
e) What do you understand by strain rosette? How it is used.
f) discuss the importance of humidity measurement in industry. Name a few processes in
which humidity control is require for efficient operation.

Q5. Attempt any 3 of the subsequent. four x three = 12
a) i) Does the accuracy of pyrometers depend on its distance from the object. If so, why?
ii) In radiation pyrometer, the energy emitted from a piece of metal was measured. The
surface emissivity of 0.82 was presumed and a temp. was determined to be 1000 Deg. K.
later investigations showed that the actual emissivity was 0.76. obtain out the fault in the
temp. determination.
b) State the factors to be considered while selecting and installation of load cell.
c) discuss the principle and working of ultrasonic flow meter.
d) discuss the working of gamma ray liquid laver sensor with neat sketch.

Q6. Attempt any 3 of the subsequent. four x three = 12
a) List electrical methods for temp. Measurement and discuss any 1 of them.
b) discuss with suitable example, feed back and feed forward control system.
c) discuss with neat sketch Lathe Tool Dynamometer.
d) List the various characteristics of the sound? discuss any 1 method of sound
measurement.

Earning:   Approval pending.