Conduction 2. Convection 3. What is resilience? Answer: The total energy stored in a body is commonly known as resilience. It means the ratio of these to the corresponding strain is a constant within the elastic limit. This constant is known as Elastic Modulus. What is mean by thermal stress? Answer: Thermal stresses are the stresses induced in a body due to change in temperature. What is meant by stress? Answer: The resistance per unit area, offered by a body against deformation is known as stress.
What is mean by strain? Answer: The ratio of change of dimension of the body to the original dimension is known as strain. What is simple harmonic motion? Answer: Any motion which repeats itself at regular intervals according to a sinusoidal law is called as harmonic motion.
What is mean by Oscillation? Answer: In general, an oscillation is a periodic fluctuation in the value of physical quantity above and below equilibrium value.
What is Damping in Physics? Answer: The phenomenon of decay in the amplitude of oscillation is known as damping. What are the 4 types of Ultrasonic Waves? Transverse ultrasonic waves or shear waves, 2. Longitudinal or compressional ultrasonic waves 3. Surface or Rayleigh waves, lamb or plates waves. What is Piezoelectric Effect?
Answer: If a piezoelectric material is subjected to pressure or squeezing or twisting, the electric charges are developed in the other two faces of the crystal. This phenomenon is called as piezoelectric effect. Give some industrial application of ultrasonic waves? Ultrasonic welding which is used to weld parts in aerospace and automobile industry.
Ultrasonic waves are used in food industry for sealing milk and juice containers. Ultrasonic waves are using in NDT Non-destructive testing for flaw detection of specimens. What is meant by Priming and Foaming? Answer: Formation of wet steam by rapid boiling of the water at the heating surface is called as priming. And the formation of stable bubbles above the surface of water inside the boiler tubes is called as foaming.
Define desalination? Answer: The process of removal of dissolved salts mostly NaCl from water is called as desalination or desalting.
What is meant by polymerization? Answer: Polymerization is the change or transition of low molecular weight constituents to high molecular weight constituents.
In simple, it is the process of making polymers from monomers. Answer: The amount of a substance deposited or dissolved as a result of passage of an electric current is proportional to the quantity of electricity passed.
What is meant by degreasing? Answer: The process of removing any oil, grease or fatty substances from the surface of any metallic body is called as degreasing. What are the organic solvents used for degreasing process?
What is meant by isothermal process? Answer: The process in which the temperature of the system remains constant is called as isothermal process.
Explain zeroth law of thermodynamics? Answer: The zeroth law of thermodynamics states that if two systems, A and B, are in thermal equilibrium with a third system, C, Then A and B are in thermal equilibrium with each other. In other words, system in same temperature are in thermal equilibrium.
Explain law of conservation of energy? What is meant by entropy? Answer: Entropy is the measure of randomness or disorderness of the system. What are thermo plastics? Answer : Thermoplastics are the materials which melts when heated and hardens when cooled. They retain their plastic properties even after heating.
Examples: polyethylene, polystyrene. What is meant by viscosity? Answer: Viscosity is defined as the property of a fluid which offers resistance to the movement of one layer of the fluid over another adjacent layer of the fluid. Define buoyancy? Answer: When a body is immersed in a fluid, an upward force is exerted by the fluid on the body. This upward force is equal to the weight of the fluid displaced by the body and is called as buoyancy.
What is meant by notch in fluid mechanics? Answer: A notch is a device used for measuring the rate of flow of a liquid through a small channel or a tank. What are the five classifications of fluids? Ideal fluid 2. Real fluid 3. Newtonian fluid 4. Non-Newtonian fluid 5. Ideal plastic fluid Ideal fluid: A fluid, which is in-compressible and is having no viscosity is known as an ideal fluid. Real fluid: A fluid, which possesses viscosity is known as real fluids. Newtonian fluid: A real fluid, which the shear stress is directly proportional to the rate of shear strain is known as a Newtonian fluid.
Non-newtonian fluid: A real fluid, in which the shear stress is not proportional to the rate of shear strain is known as non-newtonian fluid.
Ideal plastic fluid: A fluid, in which shear stress is more than the yield value and shear stress is proportional to the rate of shear strain is known as ideal plastic fluid. What is meant by capillarity? Answer: Capillarity is defined as a phenomenon of rise or fall of a liquid surface in a small tube relative to the adjacent general level of liquid when the tube is held vertically in the liquid.
Answer: It states that the pressure or intensity of pressure at a point in a static fluid is equal in all directions. What is meant by specific volume of a fluid and how do we find that?
Answer: Specific volume of a fluid is defined as the volume of a fluid occupied by a unit mass or volume per unit mass of a fluid is called as specific volume. Its found by dividing volume of a fluid by its mass. Moreover specific volume is the reciprocal of mass density.
What is meant specific gravity of a fluid? Answer: Specific gravity is defined as the ratio of the weight density of a fluid to the weight density of a standard fluid. Standard fluid for fluids is taken as water and air is taken as standard fluid for gases. Define surface tension? Answer: Surface tension is defined as the tensile force acting on the surface of a liquid in contact with a gas.
Which device is used for measuring the rate of flow of fluids through pipes? Answer: Venturimeter. What is the use of Pitot-Tube? Answer: It is a device used for measuring the velocity of flow at any point in a pipe or a channel. What are the major steps involved in manufacturing a product? Product design 2.
Material selection 3. Process planning 4. Product development 5. Inventory control 6. Quality assurance and marketing. What is the reason behind giving heat treatment to forged parts? To relive internal stresses set up during working and cooling. To normalize the internal structure of the metal.
To improve machinability. To improve hardness, strength and other mechanical properties. What are the common industrial methods of repairing and salvaging a defective casting? Answer: Once we identify the defects of castings, we will adopt reparing methods such as cold welding, hot welding, liquid metal welding, metal spraying depending on the casting. Defects in the casting are repaired with the help of appropriate sealing agents. What you meant by ductility?
Answer: It is the measure of the amount of plastic deformation a material can undergo under tensile forces without fracture and brittleness is the property opposite of ductility. Why do we add alloys into metals in manufacturing process? Answer: Usually alloys are added to metals when we need additional properties such as strength, ductility, toughness or corrosion resistance.
Alloys are also added to improve the abrasion resistance, machinability, electrical and magnetic properties of the metals. What is thermit welding and give some industrial application? Answer: In thermit welding, two pieces are joined together by the heat provided by a chemical reaction. The heating is provided by a mixture of aluminium and iron oxide.
Molten iron which is obtained from the chemical reaction will join the two pieces. Applications: 1. For joining rail tracks 2. For joining large end to end water pipes 3. For welding propeller shafts etc. What is meant by distillation? Answer: The method separating components in a liquid mixture by the distribution of substance between a gas and a liquid phase is known as distillation.
What is meant by humidification? Answer: Transfer of a liquid to a gas phase containing one or more components by contacting dry gas with pure liquid is known as humidification. What is transit energy? Answer: Energy possessed by a system which can cross its boundary is called transit energy.
Heat and work are transit energy. What is heat flux? Answer: The heat flux is the amount of heat transfer per unit area and per unit time.
What is the difference between displacement ans velocity? Answer: Displacement of a body is its change of position with reference to a certain fixed point. But velocity is the state of change of displacement of a body with respect to time. Moreover, displacement is a vector quantity.
What is the difference between linear velocity and angular velocity? Answer: Linear velocity is the rate of change of velocity of a body along a straight line with respect to time. But angular velocity is the rate of change of angular position of a body with respect to time. What are the basic parts of a reciprocating machine? Answer: Connecting rod, cylinder, piston, crank-shaft, counter weights, flange, and snout.
What are the major components of typical automotive diesel engine? Fuel injector 2. Air intake manifold 3. In rotational flow the vorticity is non zero and in irrotational flow it is zero. Define the term stability of a feed back control system?
A system is said to be stable if the output of a system after fluctuations, variations or oscilla-tions, settles at a reasonable value for any change in input. What is meant by precision? Precision is defined as the ability of instrument to reproduce a certain set of readings within a given accuracy. What is boundary layer? Boundary layer is the fluid layer in the neighbourhood of a solid boundary where the effects of fluid friction are predominant.
On what account the boundry layer exists? Boundary layer m fluid flow exists on account of fluid density. Explain the difference between laminar flow and turbulent flow.
Turbulent flow is characterised by random and erratic movements of fluid particles resulting in formation of eddies. What is the difference between path line and stream line?
A path line is a curve traced by a single fluid particle during its motion. A stream line is an imaginary line drawn in a flow field such that a tangent drawn at any point on this line represents the direction of the velocity vector.
There is no flow across the stream line. What is the difference between steady and unsteady flow? In steady flow the velocity at a given point does not change with time whereas in unsteady flow it changes with time. What is stagnation point and stagnation pressure? A stagnation point is one at which velocity is zero. Stagnation pressure is the sum of static pressure and dynamic pressure.
What is the hydraulic-grade line? It is the line which shows tne variation of piezometric head. Under what condition the thickness of thermal boundary layer and hydrody-namic boundary layer is same?
When Prandtl number is equal to unity. What keeps the shaft in floating condition in hydrodynamic journal bearing? Hydrodynamic pressure developed in the lubricant. Why the elements of higher pairs must be force closed?
This is necessary to provide completely constrained motion. What is the value of coefficient of friction for ball bearing? Ans: 0. Why belts are subject to creep? Due to uneven extension and contraction of belt. What is the ratio of damping coefficient to critical damping coefficient called? Damping factor. In which type of lubrication the starting friction is low? In hydrostatic lubrication. Ans: Yes. How the stability of empty ship increased.
By adding ballasts at the bottom level. Define Froude number. It is the square root of ratio of inertia force to gravity force. It is used to determine velocity of flow in pipe. What is the maximum efficiency of power transmission through a pipe? What is the necessary and sufficient condition for bodies in floatation to be in stable equilibrium?
Centre of gravity of body should be located below metacentre. Under what condition the thermal boundary layer thickness will be equal to the hydrodynamic boundary layer thickness? How laminar boundary layer thickness varies on a flat plate? It is proportional to the square root of the distance from the leading edge. Name the axial flow reaction turbine with adjustable vanes. Kaplan turbine. Define the degree of reaction of a turbomachine. It is the ratio of total pressure change in the rotor to that in the stage.
What is meant by relative stability? If the system is found to be stable, then it is necessary to know the stable strength or degree of stability which is called relative stability. Phase margin and gain margins are the measures of relative stability. On what factors the efficiency of a centrifugal pump depends? The efficiency of a centrifugal pump depends on size, speed and type number. Define transducer? Transducer is an element which converts the signal from one physical form to another without changing the information content of the signal.
Ans: mm. Why thin-plate orifice is frequently recommended for flow measurement in most of the cases? It is recommended because of its high accuracy, low cost, and extreme flexibility.
How the water flow from a hydrant in a city water system measured? It can be measured by allowing the flow of water from a hydrant and noting down the horizontal distance x where jet strikes the ground and the vertical distance y of outlet from ground. For the same size, length and condition of pipe, how the friction head loss changes if pipe size is varied. Under same flow conditions the friction head loss increases as the size change to the 4.
How does the capacity changes in pipe flow with increase in pipe diameter if head is constant? At constant head, capacity is proportional to d How does the head change in pipe flow with change in diameter, if capacity is constant. At constant capacity, head is proportional to. How head varies in pipe flow with change in flow, if pipe diameter is same. At constant diameter, head is proportional to flow 2. Define the term contraction coefficient. The ratio of area of jet contracted and the cross section of the orifice.
What for pycnometer is used? Pycnometer is used to measure specific gravity of the liquid. Name various functional elements of an instrumental system? Name the three stages of a generalised measuring system.
How is a Pelton turbine braked? A pelton wheel is braked by a nozzle directing a jet on the back of the buckets. What is static pressure? How is it measured.
The pressure caused on the walls of a pipe due to a fluid at rest inside the pipe or due to the flow of a fluid parallel to walls of the pipe is called static pressure. This static pressure is measured by inserting a pressure measuring tube into the pipe carrying the fluid so that the tube is at right angle to the fluid flow path.
What are the requirements of a control system? Stability, accuracy and speed of response are the three requirements of control system. What is the difference between weir, and submerged weir. Any obstruction of a streamflow over which water flows is weir. When the downstream water level rises over the weir crest, it is called submerged weir.
What is the difference between spillway and siphon spillway? Spillway is an essential part of a large dam and provides an efficient and safe means of releasing flood water that exceeds the design capacity of the reservoir.
Siphon spillway is spillway designed to discharge water in a closed conduit under negative pressure. What is the difference between culverts, stilling basin, and standpipe? Culverts are built at the points of lowest valley to pass water across the embankments of highways or railroads.
Stilling basin is transitional energy dissipating structure to avoid the damaging process by a highly accelerated spilled water. Standpipe is used principally for alleviating the transient pressures in large pipeline system.
It also works as a pressure relief valve for the upstream pipe during the turbine shut off. What do you understand by run-of-river scheme in hydro power generation? A scheme in which the discharge is varying and only that much water can be utilised for conversion as available in the river.
What is the difference between firm power and secondary power in hydro power plants? The approximate constant and continuous power which is assured at power station and would be available throughout the year is called firm power.
What is the criterion for determining economic diameter of power tunnel? The economic diameter of a power tunnel is determined such that the total value of following two factors is least i annual loss of revenue on account of power head lost due to friction.
What are the three functions served by a surge tank in a hydro plant? The three functions served by a surge tank are i flow regulation — act as a reservoir for acceptance or delivery of water to meet requirements of load changes. What is the criterion to determine the economic diameter of penstock?
The economic diameter of a penstock required to carry a discharge is the one at which annual costs due to the greater investment do not exceed the annual value of resulting increment energy output.
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