1. What is the general power rating of the hydraulic pump, used in WJM?
a) 10 kW
b) 20 kW
c) 30 kW
d) 40 kW
Explanation: The power rating of the motor of hydraulic pump, which is used in WJM is about 30 kW.
2. Which of the following are the components of intensifier present in water jet machining system?
a) Piston
b) Plunger
c) Limit switch
d) All of the mentioned
Explanation: The above mentioned components are present in the intensifier of water jet machining.
3. Intensifier increases the pressure water by which of the following values?
a) 10 – 100 MPa
b) 100 – 200 MPa
c) 200 – 400 MPa
d) 400 – 1000 MPa
Explanation: Use of intensifier is to increase the inlet water pressure to 200 – 400 MPa.
4. On which property of water, will the accumulator in Water jet machining rely on?
a) Density
b) Compressibility
c) Viscosity
d) Velocity
Explanation: Accumulator relies on compressibility of water (12% at 3800bar), in order to maintain a uniform discharge pressure in WJM.
5. What are the values of typical tube diameters in the machining system in WJM?
a) 0.1 to 1 mm
b) 1 to 6 mm
c) 6 to 14 mm
d) 14 to 25 mm
Explanation: Typical tube diameter values range between 6 to 14 mm.
6. What is the expected life of the nozzles used in WJM?
a) 10 hrs
b) 20 hrs
c) 100 hrs
d) 200 hrs
Explanation: The life that is expected from the nozzle, which is a part of machining system, is 200 hrs.
7. Which of the following does not damage the nozzle used in Water jet machining?
a) Particles of dirt
b) Mineral deposits
c) Water
d) All of the mentioned
Explanation: Only dirt particles and mineral deposits are responsible for damage of nozzle.
8. What are the uses of catcher in machining system of Water jet machining?
a) Collecting dirt
b) Collection of debris
c) Reduce noise levels
d) All of the mentioned
Explanation: Catcher in WJM is used to collect the dirt, machined debris and reduce the noise levels.
9. Distance between which components, is the stand-off distance?
a) Nozzle-inlet and work piece top
b) Nozzle-outlet and work piece-top
c) Nozzle-inlet and work piece-bottom
d) Nozzle-outlet and work piece-bottom
Explanation: Stand-off distance is the distance between the top of work piece and nozzle outlet.
10. What is the value of diameter of the jet cutting nozzle in WJM?
a) 0.01 – 0.1 mm
b) 0.1 – 0.3 mm
c) 0.3 – 0.7 mm
d) 0.7 – 1.5 mm
Explanation: In WJM, diameter of the nozzles range between 0.10 – 0.30 mm.