1. What is isentropic process?
It is always reversible and adiabatic.
2. How is the thermal efficiency of a gas turbine plant as compared to diesel engine plant?
Lower
3. For any thermodynamic process the area under the T-s diagram represents
Heat absorbed or rejected
4. What is the unit of entropy?
J/Kg K
5. For any irreversible process the net entropy change is.
Positive
6. Internal energy and enthalpy of an ideal gas are functions of
It is a function of Temperature only
7. When cp will be equal to cv For real gases?
At absolute zero temperature
8. What is stress and factor of safety?
When a mechanical component is subjected to an external static force, a resisting force is set up within the component. The internal resisting force per unit area of the component is called stress.
The factor of safety is defined as
(fs) = failure stress
allowable stress
Or (fs) = failure load
Working load
9. Mention two major differences between shaper and planer?
Shaper Planer
(a) The cutting tool reciprocates (a) Work reciprocates
(b) The work is stationary (b) Tool is stationary
(c) Meant for small work pieces (c) Meant for large work pieces
(d) Only lighter cut can be taken (d) Heavy cuts can be taken
(e) Tools are smaller in size (e) Tools are bigger in size
10. Differentiate between drilling and reaming?
Drilling Reaming
(a) It is the operation of initiating hole (a) Reaming is the operation of finishing
Sizing a drilled/bored hole
(b) It can be done at relatively high speeds (b) It should be done only at slow speeds
(c) Larger chips are produced (c) less chips are produced
(d) Drill has only two flutes (d) Reamer has more than 4 flutes
(e) Drill has chisel edge (e) Reamer has a bevel edge
11. What is Torricelli’s theorem?
According to it velocity of jet flowing out of a small opening is proportional to the square
root of head of liquid above it.
12. What are the losses in a centrifugal pump?
The losses in a centrifugal pump are:
Friction losses due to eddies in flow, leakage, friction loss due to rotation of impeller in chamber of water, gland and bearing power losses.
13. What should be done to avoid cavitations in pumps?
In order to avoid cavitations, the suction lift and the operating speed must be carefully
Chosen
14. A body is floating in water. If it is displaced slightly then about which point it will oscillate.
It will oscillate about centre of buoyancy.
15. Why heavy vehicles are made by diesel engine?
The diesel engines giving more torque.
16. What is mechanism?
A mechanism is a device designed to transform input forces and movement into a desired set of output forces and movement. Mechanisms generally consist of moving components such as gears and gear trains belt and chain drives, cam and follower mechanisms.
17. between steel, copper and brass, which conduct faster heat.
Copper has better thermal conductivity; it transfers heat faster than steel because its resulting free electrons amount to huge charge density and this density is responsible for the rather slow drift velocity unlike steel.
18. Why gas containers are mostly in a cylindrical shape?
The most efficient shape for withstanding high pressure is a sphere but that would be costly to manufacture. A cylinder with a domed top and a domed bottom is a much cheaper shape to manufacture whilst still having good strength to resist the internal gas pressure.
19. Explain absolute viscosity?
It is the ratio of shear stress and the gradient of velocity with distance between a fixed
Plate and moving plate (Its unit is Pa. s)
20. Define surface tension?
Surface tension of a liquid is the work that must be done to bring enough molecules
From inside the liquid to the surface to form one new unit area of that surface. (Its unit is
Nm/m2 or N/m)
It is always reversible and adiabatic.
2. How is the thermal efficiency of a gas turbine plant as compared to diesel engine plant?
Lower
3. For any thermodynamic process the area under the T-s diagram represents
Heat absorbed or rejected
4. What is the unit of entropy?
J/Kg K
5. For any irreversible process the net entropy change is.
Positive
6. Internal energy and enthalpy of an ideal gas are functions of
It is a function of Temperature only
7. When cp will be equal to cv For real gases?
At absolute zero temperature
8. What is stress and factor of safety?
When a mechanical component is subjected to an external static force, a resisting force is set up within the component. The internal resisting force per unit area of the component is called stress.
The factor of safety is defined as
(fs) = failure stress
allowable stress
Or (fs) = failure load
Working load
9. Mention two major differences between shaper and planer?
Shaper Planer
(a) The cutting tool reciprocates (a) Work reciprocates
(b) The work is stationary (b) Tool is stationary
(c) Meant for small work pieces (c) Meant for large work pieces
(d) Only lighter cut can be taken (d) Heavy cuts can be taken
(e) Tools are smaller in size (e) Tools are bigger in size
10. Differentiate between drilling and reaming?
Drilling Reaming
(a) It is the operation of initiating hole (a) Reaming is the operation of finishing
Sizing a drilled/bored hole
(b) It can be done at relatively high speeds (b) It should be done only at slow speeds
(c) Larger chips are produced (c) less chips are produced
(d) Drill has only two flutes (d) Reamer has more than 4 flutes
(e) Drill has chisel edge (e) Reamer has a bevel edge
11. What is Torricelli’s theorem?
According to it velocity of jet flowing out of a small opening is proportional to the square
root of head of liquid above it.
12. What are the losses in a centrifugal pump?
The losses in a centrifugal pump are:
Friction losses due to eddies in flow, leakage, friction loss due to rotation of impeller in chamber of water, gland and bearing power losses.
13. What should be done to avoid cavitations in pumps?
In order to avoid cavitations, the suction lift and the operating speed must be carefully
Chosen
14. A body is floating in water. If it is displaced slightly then about which point it will oscillate.
It will oscillate about centre of buoyancy.
15. Why heavy vehicles are made by diesel engine?
The diesel engines giving more torque.
16. What is mechanism?
A mechanism is a device designed to transform input forces and movement into a desired set of output forces and movement. Mechanisms generally consist of moving components such as gears and gear trains belt and chain drives, cam and follower mechanisms.
17. between steel, copper and brass, which conduct faster heat.
Copper has better thermal conductivity; it transfers heat faster than steel because its resulting free electrons amount to huge charge density and this density is responsible for the rather slow drift velocity unlike steel.
18. Why gas containers are mostly in a cylindrical shape?
The most efficient shape for withstanding high pressure is a sphere but that would be costly to manufacture. A cylinder with a domed top and a domed bottom is a much cheaper shape to manufacture whilst still having good strength to resist the internal gas pressure.
19. Explain absolute viscosity?
It is the ratio of shear stress and the gradient of velocity with distance between a fixed
Plate and moving plate (Its unit is Pa. s)
20. Define surface tension?
Surface tension of a liquid is the work that must be done to bring enough molecules
From inside the liquid to the surface to form one new unit area of that surface. (Its unit is
Nm/m2 or N/m)
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