Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Winter 7th Sem 2171912 Oil Hydraulics And Pneumatics Previous Question Paper
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER?VII (NEW) EXAMINATION ? WINTER 2020
Subject Code:2171912 Date:21/01/2021
Subject Name:Oil Hydraulics & Pneumatics
Time:10:30 AM TO 12:30 PM Total Marks: 56
Instructions:
1. Attempt any FOUR questions out of EIGHT questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1 (a) Mention the major area of application of hydraulic system.
03
(b) State the advantages and disadvantages of pneumatic system.
04
(c) Explain the following properties of hydraulic fluid.
07
(i)
Bulk Modulus
(ii)
Viscosity
(iii)
System Compatibility
(iv)
Flash Point
(v)
Demulsibility
(vi)
Fire Resistance
(vii) Lubricity
Q.2 (a) Draw the standard symbols of adjustable pressure relief valve, adjustable
03
pressure reducing valve and pressure compensated flow control valve.
(b) Compare positive displacement pump with Roto-dynamic pump.
04
(c) Explain the construction and working of external gear pump using
07
schematic diagram.
Q.3 (a) Enlist and explain the functions of hydraulic fluid.
03
(b) State different types of pressure control valves. Explain working of each
04
one with the help of neat sketch.
(c) Give different types of air compressors. Sketch multistage reciprocating
07
air compressor and enumerate different parts of compressor. What are
selection criteria for compressor?
Q.4 (a) What is the significance of heating and cooling devices in hydraulic
03
system?
(b) Explain construction and working of Quick Exhaust Valve.
04
(c) Explain cracking pressure and pressure override in context of a pressure
07
relief valve. Draw the pressure override characteristics for an ideal
condition of conventional spring loaded PRV.
Q.5 (a) What is a check valve? Show various uses of a check valve in the
03
hydraulic circuit.
(b) Explain different types of fire resistance hydraulic fluid.
04
(c) Draw Symbol of filter & explain the working of by-pass type filter.
07
Q.6 (a) With neat sketch explain construction and working of push button
03
operated spring return 3/2 DCV.
(b) Draw and explain the regenerative circuit. What are the advantages and
04
disadvantages of it?
1
(c) What is the significance of FRL unit in pneumatic system? Explain
07
construction and working of lubricator with neat sketch.
Q.7 (a) Give brief overview on hydrostatic transmission system.
03
(b) What is the significance of center condition in 4/3 DCV? Which center
04
condition is used in which application, explain each in detail.
(c) Enlist different types of hydraulic cylinders. What is cushioning
07
assembly, explain using schematic diagram.
Q.8 (a) Classify automation by control system.
03
(b) Enlist different types of accumulators. Explain dead weight and spring
04
loaded accumulators. Differentiate between them.
(c) Design a pneumatic system to control double acting cylinder using 5/2
07
Air-Air valve. The piston should extend when two push buttons are
pressed simultaneously and it should retract automatically after specified
time delay. If the emergency push button is pressed than the piston should
retract immediately.
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This post was last modified on 04 March 2021