A system comprising of a pure substance executes reversibly a cycle 1-2-3-4-1 consisting
of two isentropic and two isochoric processes as shown in the
Which one of the following is the correct representation of this cycle on the tempertureentropy
Match List-I (Process index 'n') with List-Ii (Ts traces) and select the correct answer using the
code given below the list
Direction : Each of the next consists of two statements, one labelled as the 'Assertion (A)' and the other as 'Reason (R)'. You are to examine these two statements carefully and select the answers to these items using the codes given below:
Assertion (A): An air filled balloon released from the ground goes up and up till it reaches a certain elevation and floats in the air.
Reason (R): with increase in elevation the temperature of the atmospheric air increases and so the density decreases.
When a system is taken from state A to state B along the path A-C-B, 180 kJ of the heat flows into the system and it does 130 kJ of work (as shown in the figure below):
How much heat will flow into the system along the path A-D-B if the work done by it along the path is 40 kJ?
A system while undergoing a cycle A-B-C-D- A has the values of heat and work transfers as given
in the table
The power developed in kW is, nearly,
In a throttling process, which one of the following parameters remains constant ?
At critical point the enthalpy of vaporization is
Joule-Thomson coefficient is defined as
The specific heat at constant volume is
When a system changes its state from one equilibrium state to another equilibrium state, thenthe path of successive states through which the system has passed, is known as
When the gas is cooled at constant pressure,
The polytropic index (n) is given by
In aqua-ammonia and Lithium -bromide water absorption refrigeration systems, the refrigerantsare respectively
The desirable property of a refrigerant is
Physical Properties of Refrigerants
Low Condensing Pressure.
High Evaporator Pressure.
High Critical Pressure.
High Vapor Density.
High Dielectric strength.
High Latent Heat of Vaporization.
High Heat Transfer Coefficient.
The refrigerant used for absorption refrigerators working heat from solar collectors is mixture ofwater and
The maximum COP for the absorption cycle is given by (TG = generator temperature TC=environment temperature, TE= refrigerated space temperature)
The coefficient of performance of a refrigeration working on a reversed Carnot cycel is 4. Theratio of the highest absolute temperature to the lowest absolute temperature is
In a petrol engine, the fuel supplied to the engine cylinder is mixed with required quanity of air andthe mixture is ignited with a
In a petrol engine, the mixture has the lowest pressure at the
The diameter of the cylindrical shell of a Lancashire boiler is about
The correct sequence of the given four cycles on T-s plane in figure 1, 2, 3, 4
(A) Rankine, Otto, Carnot and Diesel
(B) Rankine, Otto, Diesel and Carnot
(C) Otto, Rankine, Diesel and Carnot
(D) Otto, Rankine, Carnot and Diesel
The two reference fuels used for cetane rating are
The object of providing masked inlet valve in the air passes of compression ignition engines isto
List-I gives the different terms related to combustion while List-II gives the outcome of
the events that follows. Match List-I with List-II and select the correct answer using the codes given below the lists:
What is the main objective of supercharging of the engine?
Which of the following is boiler mounting?
Induced draught fans of a large steam generator have
Benson boiler is one of the high pressure boilers having
Which one of the following safety devices is used to protect the boiler when the water level fallsbelow a minimum level ?
A gas turbine works on which one of the following cycles?
The most commonly used moderator in nuclear power plants is
A device used to heat feed water by utilising the heat in the exhaust flue gases before leavingthrough the chimney, is known as
An air preheater
The object of producing draught in a boiler is
A piezometer tube is used only for measuring
When a body is placed over a liquid, it will sink down if
The Euler's equation for the motion of liquids is based upon the assumption that
The discharge over a right angled notch is
The unit power developed by a turbine is
The specific speed of a turbine is given by the equation
A turbine develops 10 000 kW under a head of 25 metres at 135 r.p.m. Its specific speed is
For 450 m head of water,...... shall be used.
Correct Answer :- a
Explanation : For 450 m head of water, Pelton wheel shall be used.
A Pelton turbine or Pelton wheel is a type of hydro turbine (specifically an impulse turbine) used frequently in hydroelectric plants. These turbines are generally used for sites with heads greater than 300 meters.
The water in a Pelton turbine is moving quickly and the turbine extracts energy from the water by slowing the water down, which makes this an impulse turbine.
Which one of the following is the bulk modulus K of a fluid? (Symbols is have the usual meaning)
An oil of specific gravity 0.9 has viscosity of 0.28 stokes at 38ºC. What will be its viscosity in Ns/m2?
If angle of contact of a drop of liquid is acute then
Resultant pressure of the liquid in case of an immersed body acts through with one of thefollowing?
A hydraulic jump occurs in a channel
The thermal or temperature stress is a function of
The total strain energy stored in a body is termed as
When a load on the free end of a cantilever beam is increased, failure will occur
Two simply supported beams 'A' and 'B' of same breadth and depth carries a central load W asshown fig. The deflection of beam 'B' will be ...... as that of beam 'A'.
The polar moment of inertia of a hollow shaft of outer diameter (D) and inner Diameter (d) is
Which one of the following expresses the total elongation of a bar of length L with a constant
cross-section of A and modulus of Elasticity E hanging vertically and subject to its own weight
The number of independent elastic constants required to express the stress-strain relationshipfor a linearly elastic isotropic material is
If the ratio G/E (G= Rigidity modulus, E= Young's modulus of elasticity) is 0.4, then what is the valueof the Poisson ratio?
Match List – I (State of stress) with List -II (kind of loading) and select the correct answer using
the codes given below the lists
Auto-frettage is a method of
The maximum bending moment in a simply beam of length L loaded by a concentrated load W at
the midpoint is given by
In a beam of circular cross-section, the shear stress variation across a cross section is
The moment of a force
The term 'centroid' is
Moment of inertia of a hollow rectangular section as shown in fig. about X-X axis, is
The friction experienced by a body, when in motion, is known as
Which one of the following figures represents the maximum shear stress Theory or TRESCA
A rotating shaft carrying a unidirectional transverse load is subjected to :
Removal of metal particles from the raceway of a rolling contact bearing is a kind of failure ofbearing known as
The resistance of fatigue of a material is measured by
The maximum shear stress theory is used for
The maximum normal stress theory is used for
Rankine's theory is used for
A ball is thrown upwards and it returns to the ground describing a parabolic path which of thefollowing remains constant ?
The number of instantaneous centres of rotation for a 10 link kinematic chain is
In a Kinematic chain, a quaternary joint is equivalent to :
Flywheel absorbs energy during those periods of crank rotation when
Figure given below shows a spring-mass system where the mass m is fixed in between tw3o
springs of stiffness S1 and S2. What is the equivalent spring stiffness?
The sensitivity of an isochronous governor is
When the elements of a pair are kept in contact by the action of external forces, the pair is saidto be a
In a single slider crank chain
The included angle for the V-belt is usually
For two governors A and B, the lift of sleeve of governor A is more than that of governor B, fora given fractional change in speed. It indicates that
Match List-I (Heat treatment) with List-II (Effect on the properties) and select the correct
answer using the codes given below the lists:
Match List-I (Name of material) with List-II (% Carbon range) and select the correct answer
using the codes given below the lists
'Tempering' of quenched martensitic steel is necessary to improve the
Resilience of a material becomes important when it is subjected to
Match List-I (Product) with List-II (Process of Manufacture) and select the correct answer
using the codes given below the lists :
A. Automobile piston in aluminium alloy
B. Engine crankshaft in spheroidal graphite iron
C. Carburettor housing in aluminium alloy
D. Cast titanium blades
1. Pressure die-casting
2. Gravity die-casting
3. Sand casting
4. Precision investment casting
5. Shell moulding
In gating system design, which one of the following is the correct sequence in which chokearea, pouring time, pouring basin and sprue sizes are calculated ?
In wire drawing process, the bright shining surface on the wire is obtained if one
Best position on crank for blanking operation in a mechanical press is
Which of the following materials is used in the manufacture of extrusion nozzles?
In oxy-acetylene gas welding, for complete combustion, the volume of oxygen required perunit of acetylene is
Oxyacetylene reducing flame is used while carrying out the welding on
In arc welding, arc is created between the electrode and work by
An arc is generated between two conductors of electricity, cathode and anode (considering direct current, DC), when they are touched to establish the flow of current and then separated by a small distance. An arc is a sustained electric discharge through this ionised gas column called plasma between the two electrodes.
Which one of the following is not used as abrasive material in grinding wheels ?
The cutting tool material required to sustain high temperature is
In arc welding, the temperature of heat produced by the electric arc is of the order of
The temperature of the inner luminous cone of neutral flame is about
Segmental chips are formed during machining
The type of tool used on milling machine andbroaching machine is
A single point tool has
Carbide tipped tools usually have
Correct Answer :- a
Explanation : Carbide tip has a high amount of carbon which make the metal brittle and increases its hardness. This increase in hardness causes the tool to have a negative value of rake angle.