Hydraulics & Pneumatics Test Questions - Set 7

1)   What causes reduction in speed of the piston rod when the hydraulic cylinder is cushioned?

a. oil flow through small space
b. back pressure created in the system
c. both a. and b.
d. none of the above
Answer  Explanation 

ANSWER: both a. and b.

Explanation:
No explanation is available for this question!


2)   Which of the following is a hydraulic cylinder based on application?

a. welded
b. bolted
c. ram
d. all of the above
Answer  Explanation 

ANSWER: ram

Explanation:
No explanation is available for this question!


3)   What happens when supply of oil to a single acting cylinder is stopped?

a. no pressure is exerted on the system
b. more pressure is exerted on the piston
c. less pressure is exerted on the piston
d. none of the above
Answer  Explanation 

ANSWER: less pressure is exerted on the piston

Explanation:
No explanation is available for this question!


4)   When does expansion of spring and retraction of cylinder take place in spring type single acting cylinder?

a. oil pressure exerted is less than spring compression pressure
b. oil pressure exerted is more than spring compression pressure
c. oil pressure exerted and spring compression pressure are same
d. none of the above
Answer  Explanation 

ANSWER: oil pressure exerted is less than spring compression pressure

Explanation:
No explanation is available for this question!


5)   Double acting cylinder can be used as a single acting cylinder

a. True
b. False
Answer  Explanation 

ANSWER: True

Explanation:
No explanation is available for this question!


6)   In a telescopic cylinder, as the number of stages increase

a. diameter of piston rod also increases
b. diameter of piston rod decreases
c. diameter of the piston rod remains the same
d. none of the above
Answer  Explanation 

ANSWER: diameter of piston rod decreases

Explanation:
No explanation is available for this question!


7)   Why are bleed off circuits used?

a. bleed off circuit is used to restrict the flow of fluid into the hydraulic cylinder
b. bleed off circuit is used to restrict the flow of fluid out of the hydraulic cylinder
c. bleed off circuits are used to reduce the speed of actuator
d. all of the above
Answer  Explanation 

ANSWER: bleed off circuits are used to reduce the speed of actuator

Explanation:
No explanation is available for this question!


8)   Which of the following is applicable for bleed off circuits?

a. bleed off circuits develop heat in the system
b. bleed off circuits are used for resistive loads
c. bleed off circuits are used for runaway loads
d. all of the above
Answer  Explanation 

ANSWER: bleed off circuits are used for resistive loads

Explanation:
No explanation is available for this question!


9)   What is the function of sequence valve used in hydraulic circuits?

a. sequence valves are used to perform number of operations one after the other after the set pressure is reached
b. sequence valves are used to perform number of operations continuously before the set pressure is reached
c. sequence valves after reaching set pressure oil is flown to the tank
d. all of the above
Answer  Explanation 

ANSWER: sequence valves are used to perform number of operations one after the other after the set pressure is reached

Explanation:
No explanation is available for this question!


10)   When is a pressure reducing valve used?

a. it is used when higher pressure than system pressure is required
b. it is used when lower pressure than system pressure is required
c. when absolutely zero pressure is required
d. all of the above
Answer  Explanation 

ANSWER: it is used when lower pressure than system pressure is required

Explanation:
No explanation is available for this question!


11)   How is strong magnetic field in a solenoid achieved?

a. strong magnetic field in a solenoid is achieved, if coil acts as conductor
b. coil is surrounded by a iron frame
c. iron core is placed at the centre of the coil
d. all of the above
Answer  Explanation 

ANSWER: all of the above

Explanation:
No explanation is available for this question!


12)   What is the DC range of of solenoids in pneumatic systems?

a. 12 V and 24 V
b. 110 V and 220 V
c. both a. and b.
d. none of the above
Answer  Explanation 

ANSWER: 12 V and 24 V

Explanation:
No explanation is available for this question!


13)   Which of the following is used an output device on a ladder diagram?

a. proximity sensor
b. detent switch
c. relay
d. all of the above
Answer  Explanation 

ANSWER: relay

Explanation:
No explanation is available for this question!


14)   The output device on a ladder diagram is represented by

a. square
b. circle
c. rectangle
d. semicircle
Answer  Explanation 

ANSWER: circle

Explanation:
No explanation is available for this question!


15)   In mnemonics instructions, what does I in LDI indicate?

a. switch is normally open
b. switch is normally closed
c. it indicates operating of second switch
d. none of the above
Answer  Explanation 

ANSWER: switch is normally closed

Explanation:
No explanation is available for this question!


16)   In industrial applications hydraulic fluids have viscosity grade ranging from

a. 20 to 50
b. 70 to 95
c. 46 to 68
d. 15 to 44
Answer  Explanation 

ANSWER: 46 to 68

Explanation:
No explanation is available for this question!


17)   High viscosity fluids have

a. low pressure drop
b. less power consumption
c. slow operation
d. all of the above
Answer  Explanation 

ANSWER: slow operation

Explanation:
No explanation is available for this question!


18)   What is viscosity index?

a. effect of pressure on changes in viscosity
b. effect of temperature on changes in viscosity
c. effect of resistance between two surfaces
d. none of the above
Answer  Explanation 

ANSWER: effect of temperature on changes in viscosity

Explanation:
No explanation is available for this question!


19)   Highest temperature at which a fluid in hydraulic system flows is called its pour point.

a. True
b. False
Answer  Explanation 

ANSWER: False

Explanation:
No explanation is available for this question!


20)   Which property decides the behavior of fluid when mixed with water?

a. pour point
b. demulsibility
c. viscosity
d. oxidation
Answer  Explanation 

ANSWER: demulsibility

Explanation:
No explanation is available for this question!