- For flow through pipes, the maximum transmission efficiency that can achieve is:
- 67%
- 100%
- 50%
- 40%
- The unit of Chezy’s constant C in the Chezy’s formula is
- m1/2/s
- None of these
- m/s
- m/s2
- The ratio of the pitch diameter of Pelton wheel to the diameter of the jet is called:
- Jet ratio
- Speed ratio
- Wheel ratio
- None of these
- The hydraulic efficiency of a turbine with mean bucket diameter 1 m and running at 1000 rpm with net head 700 m when the side clearance angle is 15 degree and discharge of 100 liters/s is:
- 97%
- 60%
- 70%
- 85%
- The head loss due to friction for the flow of water through penstocks can be minimized by:
- Increasing the diameter of penstock
- Decreasing the diameter of penstock
- Increasing the length of penstock
- increasing the velocity of flow
- The head against which the centrifugal pump has to work is called:
- Manometric head
- Static head
- Suction head
- Delivery head
- An example of a turbine with high head and low specific speed is:
- Pelton
- Kaplan
- Francis
- None of these
- Which parameter remains constant during Joule-Thomson expansion?
- Pressure
- Temperature
- Enthalpy
- Volume
- For an ideal gas the compressibility factor is:
- Unity
- Zero
- Infinity
- None
- A heat pump works on reversed Carnot cycle has a COP of 5. If it works as a refrigerator taking 1kW of work input, the refrigerator effect will be:
- 4kW
- 1kW
- 2kW
- 3kW
- The value of Universal gas constant is
- None of these
- 8.314 J/kgK
- 83.14 kJ/kgK
- 8.3 14 kJ/kgK
Value of Universal gas constant is 8.314 J / mol. K
- Which one of the following is the extensive property of the system?
- Volume
- Pressure
- Temperature
- Density
- Which parameter remains constant during a reversible adiabatic process?
- Entropy
- Enthalpy
- temperature
- Internal Energy
- Second law of thermodynamics defines
- Entropy
- Efficiency
- Enthalpy
- Internal Energy
- Which one of the following relation defines Helmholtz function F?
- U - TS
- H + TS
- H - TS
- U ÷ TS
- Which one of the following parameter is significant to ascertain chemical equilibrium of a system?
- Gibbs Function
- Helmholtz Function
- Clapeyron equation
- Maxwell reaction
- Which of the following cast iron consist of carbon in rosette form?
- Malleable cast iron
- White cast iron
- Grey cast iron
- Nodular cast iron
- Puddling is the process employed for converting:
- Pig Iron into wrought iron
- Iron ore into pig iron
- Pig iron into cast iron
- None of these
- Which is the magnetic allotrope of iron?
- α iron
- β iron
- γ iron
- None of these
- 18/8 stainless steel contains:
- 18% Chromium, 8% Nickel
- 18% Vanadium, 8% Chromium
- 8% Tungaton, 8% Nickel
- 18% Tungston, 8% Chromium
- Muntz metal contains copper and zinc in the ratio:
- 3:2
- 1:1
- 2:3
- 1:4
- Monel metal is an alloy of
- Nickel and Copper
- Copper and Chromium
- Nickel and Chromium
- None of these
- The hardness of a lathe bed material should be measured by:
- Shore scleroscope
- Brinell Hardness tester
- Rockwell tester
- Vickers Hardness tester
- White metal is an alloy of lead with:
- Tin
- Aluminium
- Zinc
- Bismuth
- Which one of the following is not an application of forging?
- Steel balls of ball bearing
- Rail sections
- Chisels
- Brake pedal of an automobile
- The electric resistance welding operates with:
- High current and low voltage
- Low current and high voltage
- Low current and low voltage
- High current and high voltage
- Spot welding, projection welding and seam welding belong to the category of:
- Resistance welding
- Arc welding
- Thermit welding
- Forge welding
- The number of Zones of heat generation in spot welding are:
- 5
- 2
- 3
- 7
- The ratio between oxygen and acetylene gases for neutral flame in gas welding is:
- 1:1
- 2:1
- 1:2
- 4:1
- Thermit used in thermit welding process is a mixture of:
- Aluminium and Iron Oxide
- CharcoL and Aluminium
- Charcol and Iron Oxide
- Charcol, Aluminium and Iron Oxide
- Which of the following welding methods uses pool of molten metal?
- Submerged arc welding
- Resistance welding
- Plasma welding
- None of these
- The welding zone in the TIG arc welding is shielded by an atmosphere of:
- Helium
- Oxygen Gas
- CO2
- Hydrogen
- Which of the following welding techniques uses a non consumable electrode?
- TIG
- MIG
- Submerged arc
- Thermit
- Vacuum environment is required in:
- Electron beam welding
- Ultrasonic welding
- Laser beam welding
- None of these
- High Speed electron beam of electron beam welding is focused on the weld spot using:
- Magnetic lens
- Vacuum lens
- Inert gas lens
- Optical lens
- Weld spatter is
- a welding defect
- an electrode
- a flux
- none of these
- A composite wall of a furnace has two layers of equal thickness with thermal conductivities in the ratio 3:2. What is the ratio of temperature drop across the two layers:
- 2:3
- 3:2
- 1:2
- None of these
- Critical thickness of insulation for a sphere with thermal conductivity k and convective heat transfer coefficient h is given by:
- 2k/h
- k/h
- k/4h
- k/2h
- For a perfectly black body: (α - Absorptivity, ρ - Reflectivity and τ- Transmitivity)
- α=1, ρ=0, τ=0
- α=ρ=0, τ=0
- α=τ=0, ρ=0
- None of these
- The intensity of solar radiation on earth is:
- 1 kW/m2
- 0.5 kW/m2
- 2 kW/m2
- 5 kW/m2
- If the temperature of a hot body is increased by 50% the amount of radiation emitted by it would increase by nearly:
- 500%
- 60%
- 100%
- 200%
- The value of shape factor for two infinite parallel planes separated by a distance x is:
- 1
- 0
- 0.5
- x
- The ratio of heat transfer by convection to that by conduction is called:
- Nusselt Number
- Stanton Number
- Biot Nunaber
- Peclet Number
- Which dimensionless number has a significant role in natural convection?
- Grashoff’s Number
- Peclet Number
- Mach Number
- None of these
- For the same operating temperature limits the COP of the heat pump equals:
- 1 + COP of Refrigerator
- COP of refrigerator
- COP of Refrigerator -1
- None of these
- A Carnot refrigerator rejects 3000 kJ of heat at 400 K while using 1000 kJ of work. The lowest operating temperature in the cycle should be about:
- 267 K
- 288 K
- 300 K
- 273 K
- During which component of vapour compression refrigeration system, the enthalpy remains constant:
- Throttle Valve
- Evaporator
- compressor
- None of these
- One tone of refrigeration is equal to:
- 3.5kW
- 5kW
- 10kW
- 125kW
- Knocking tendency in SI engine reduces with increasing:
- Engine Speed
- Compression Ratio
- Wall temperature
- None of these
- The two reference fuels used for cetane rating are:
- Cetane and isooctane
- Cetane and tetra ethyl lead
- Cetane and alpha methyl naphthalene
- None of these
- For a two stage reciprocating air compressor with perfect inter cooling the work input will be minimum if the supply pressure P1, the inter-cooler pressure P2 and the delivery pressure P3 satisfy the relation:
- P2 = (P1*P2)0.5
- P2 = (P1+P3)/2
- P2 P1/P3
- None of these
- Optimum pressure ratio for maximum specific output for ideal gas turbine power plant operating at initial temperature of 300 K and the maximum temperature of 1000 K is closer to:
- 8
- 4
- 12
- 16
- The use of regeneration in a gas turbine cycle increases:
- Efficiency but has no effect on output
- Output but has no effect on efficiency
- Both efficiency and output
- None of these
- Which one of the following is a lower pair?
- Shaft in a bearing
- Cam and follower
- Toothed gearing
- None of these
- The average tensions on the tight and slack side of a flat belt drive system are 700 N and 400 N respectively. If the linear velocity of the belt is 5 m/s, the power transmitted by the system would be about:
- 1.5 kW
- 3 kW
- 5 kW
- 10 kW
- In a 6 x 20 wire rope, number 6 indicates:
- Number of strands in the wire rope
- Diameter of the wire rope in mm
- Number of wires
- None of these
- The motion transmitted between the teeth of two spur gears is generally:
- Partly sliding and partly rolling
- Sliding
- Rolling
- Rotary
- The product of circular pitch and diametral pitch equals:
- π
- 1
- Infinity
- None of these
- In a flat belt drive, the belt can be subjected to maximum tension T and a centrifugal tension Tc. For maximum power transmission
- T = 3Tc
- T = Tc
- T = 2Tc
- T = 4Tc
- Which of the following is not a common section of V belts?
- F
- C
- E
- A
- A rack is a gear of infinite :
- Diameter
- Pitch
- Module
- Number of teeth
- The circular pitch of a toothed wheel with 24 teeth and a module of 4.25 mm is:
- 13.35 mm
- 1.35 mm
- 4.25mm
- 6.67 mm
- The maximum efficiency of a worm and worm wheel system in terms of friction angle φ is:
- (1-sin φ)/(1+sin φ)
- (1-cos φ)/(1+cos φ)
- (1-sin φ)/(1+cos φ)
- (1-tan φ)/(1+tan φ)
- In a multiple disc clutch n1 and n2 are the number of discs in the driving and driven shafts respectively. Then the number of pairs of contact surface is:
- n1+n2-1
- n1+n2
- n1-n2
- None of these
- The type of brakes commonly used in automobiles is:
- Shoe brake
- Band brake
- Band and Block brake
- None of these
- A reverted gear train is one in which the output and input shaft:
- Are coaxial
- Are at right angles to each other
- Rotate in opposite directions
- None of these
- When two spur gears having involute profiles on their teeth engage the line of action is tangential to:
- Base circle
- Pitch circle
- Dedundum circle
- Addendum circle
- A 60 mm long and 6 mm thick fillet weld carries a steady load of 15 kN along the weld. The shear strength of the weld material is 200 Mpa. The factor of safety is :
- 3.4
- 2.4
- 1.8
- 6.8
- In a butt weld joint the throat of weld as compared to size of the weld is in the ratio:
- 1:1
- 2:1
- 1:2
- 1:3
- A circular solid rod of diameter d welded to a right flat plate by a circular fillet weld of throat thickness t is subject to a twisting moment T. The maximum shear stress induced in the weld is
- 2T/πtd2
- 2T/πtd3
- T/πtd2
- 4T/πtd2
- In a BSW thread the angle between the flanks is:
- 55°
- 29°
- 47.5°
- 60°
- A high pressure angle for spur gears leads to:
- Wide base and stronger teeth
- Minimum axial thrust
- More interference
- None of these
- A worm has a lead angle of 22.5°. This corresponds to a helix angle of:
- 67.5°
- 22.5°
- 45°
- 55°
- The ratio between the mean diameter of the coil and diameter of wire is called:
- Spring index
- Spring rate
- Spring Constant
- Spring stiffness
- A spring with spring constant s has been cut into n equal parts. Each portion of the cut spring will have a spring constant, equal to:
- ns
- s
- s/n
- n/s
- Which of the following is not a friction clutch?
- Jaw clutch
- Plate clutch
- Cone clutch
- Centrifugal clutch
- The maximum stress induced in a spiral spring in terms of Moment applied M, breadth of strip b and thickness of strip t is:
- 12M/bt2
- 4M/bt2
- 8M/bt2
- 16M/bt2
- In design of helical springs the spring index is usually taken as:
- 3
- 10
- 12
- 16
- The stress induced in the circular section wire of a closed coil helical spring in terms of axial load W, mean coil diameter D and wire diameter d is:
- 8WD/πd3
- 12WD/πd3
- 16WD/πd3
- 32WD/πd3
- Spring stiffness is
- Load per unit deflection
- Load carrying capacity of the spring
- Ratio of mean coil diameter to wire diameter
- None of these
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