Basics of Hydraulics - Mechanical Engineering (MCQ) questions and answers

1)   Generally liquids are non-compressible but when a large pressure of 70 bar is applied, petroleum oil can be compressed up to

a. 0.5% of its original volume
b. 1% of its original volume
c. 5% of its original volume
d. none of the above
 Answer  Explanation ANSWER: 0.5% of its original volume Explanation: No explanation is available for this question!

2)   Which formula is used to calculate head loss in valves?

a. K2 ( v / 2 g )
b. K ( v / 2 g )
c. K ( v2 / 2 g )
d. none of the above
 Answer  Explanation ANSWER: K ( v2 / 2 g ) Explanation: No explanation is available for this question!

3)   Calculate area of a pipe if, flow rate is 20 l/min and flow velocity is 5 cm/s.

a. 66.66 cm2
b. 60 cm2
c. 62 cm2
d. none of the above
 Answer  Explanation ANSWER: 66.66 cm2 Explanation: No explanation is available for this question!

4)   What are the reasons causing pressure drop in hydraulic systems?

1. long length of pipe
2. friction
3. type of fluid
4. losses in valves and bends

a. 1 and 4
b. only 1
c. 2 and 3
d. all of the above
 Answer  Explanation ANSWER: all of the above Explanation: No explanation is available for this question!

5)   Head loss due to friction (hf) is a function of

3. length to diameter ratio
4. diameter to length ratio
5. friction factor

a. 1, 2 and 3
b. 1, 4 and 5
c. 1, 3 and 5
d. all of the above
 Answer  Explanation ANSWER: 1, 3 and 5 Explanation: No explanation is available for this question!

6)   Head loss hf due to friction is given by

a. 4 ƒ l v2 / g d
b. 4 f2 l ν / 2 g d
c. 2 ƒ l v 2 / 2 g d
d. 4 ƒ l v2 / 2 g d
 Answer  Explanation ANSWER: 4 ƒ l v2 / 2 g d Explanation: No explanation is available for this question!

7)   In pressure compensated vane pump,

1. having variations in eccentricity between rotor and cam ring gives variable displacement
2. as eccentricity between rotor and cam decreases, flow of fluid  decreases
3. as eccentricity between rotor and cam decreases, flow of fluid  increases
4. having variations in eccentricity between rotor and cam ring gives fixed displacement

a. 1 and 3
b. 3 and 4
c. 2 and 4
d. 1 and 2
 Answer  Explanation ANSWER: 1 and 2 Explanation: No explanation is available for this question!

8)   Cam ring of unbalanced vane pump is

a. round
b. elliptical
c. both a. and b.
d. none of the above
 Answer  Explanation ANSWER: round Explanation: No explanation is available for this question!

9)   Balanced vane pumps are designed to have

a. fixed displacement
b. variable displacement
c. both fixed and variable displacement
d. none of the above
 Answer  Explanation ANSWER: fixed displacement Explanation: No explanation is available for this question!

10)   Which of the following statements is false for vane pumps?

a. wear in contact surfaces occurs due to continuous contact between vane tips and the cam ring
b. different sizes of cartridge kits can be replaced in same vane pump
c. elliptical cam ring is replaced by round cam ring to reduce unbalanced forces
d. none of the above
 Answer  Explanation ANSWER: elliptical cam ring is replaced by round cam ring to reduce unbalanced forces Explanation: No explanation is available for this question!

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