(Papers) SSC Junior Engineer Exam Paper - 2016 "held on 02 March 2017 "Morning Shift( General Engineering)
QID : 801 - A football was inflated to a gauge pressure of 1 bar when the ambient temperature was 15°C. When the game started next day, the air temperature at the stadium was 5°C. Assume that the volume of the football remains constant at 2500 cm3. Gauge pressure of air to which the ball must have been originally inflated so that it would equal 1 bar gauge at the stadium is _____.
Options:
1) 2.23 bar
2) 1.94 bar
3) 1.07 bar
4) 1 bar
Correct Answer: 1.07 bar
QID : 802 - The engine oil at 150 °C is cooled to 80 °C in a parallel flow heat exchanger by water entering at 25 °C and leaving at 60 °C. The exchanger effectiveness will be _____.
Options:
1) 0.36
2) 0.46
3) 0.56
4) 0.66
Correct Answer: 0.56
QID : 803 - The atomic packing factor is the highest in which of the following cubic lattice system?
Options:
1) Simple Cubic
2) Body Centered Cubic (BCC)
3) Face Centered Cubic (FCC)
4) Diamond Cubic
Correct Answer: Face Centered Cubic (FCC)
QID : 804 - The valves mounted on the boilers which change the direction of flow of steam by 90° and valves fitted in the pipelines which allow the steam in the same direction are respectively called as _____.
Options:
1) Stop valves and junction valves
2) Junction valves and stop valves
3) Junction valves and safety valves
4) Feed safety valves and stop valves
Correct Answer: Junction valves and stop valves
QID : 805 - Which of the following are boiler mountings and not boiler accessories ?
A] Pressure gauge
B] Air preheater
C] Superheater
Options:
1) B and C only
2) A only
3) A, B and C
4) A and C only
Correct Answer: A only
QID : 806 - Entropy is a measure of _____.
Options:
1) Reversible heat transfer
2) System efficiency
3) Degree of randomness
4) System temperature
Correct Answer: Degree of randomness
QID : 807 - Gibbs free energy is considered at which one of the following condition?
Options:
1) Isothermal, isochoric
2) Isobaric, isochoric
3) Isothermal, isobaric
4) None of these
Correct Answer: Isothermal, isobaric
QID : 808 - In vapour absorption refrigeration systems, which of the following fluids are commonly used?
Options:
1) air and water
2) sulphur dioxide and water
3) ammonia and water
4) freon and water
Correct Answer: ammonia and water
QID : 809 - In a cross compound steam engine _____.
Options:
1) one high and one low pressure cylinder are set side by side, driving the same shaft, cranks being set 90° apart
2) two cylinders are centred on the same piston rod, the 1.p. cylinder being placed nearest the crankshaft
3) two cylinders are set at 90°, usually to save floor space
4) None of these
Correct Answer: two cylinders are centred on the same piston rod, the 1.p. cylinder being placed nearest the crankshaft
QID : 810 - Which of the following is expected to have highest thermal conductivity?
Options:
1) steam
2) solid ice
3) melting ice
4) water
Correct Answer: solid ice
QID : 811 - A reversible thermodynamic cycle containing only three processes and producing work is to be constructed. The constraints are
A. there must be one isothermal process
B. there must be one isentropic process
C. maximum and minimum cycle pressures and the clearance volume are fixed, and
D. polytropic processes are not followed Then, the number of possible cycles is
Options:
1) 1
2) 2
3) 3
4) 4
Correct Answer: 1
QID : 812 - Which combination of the following statements is correct?
The incorporation of re-heater in a steam power plant
A. Always increases the thermal efficiency of the plant
B. Always increases the dryness fraction of steam at condenser inlet
C. Always increases the main temperature of heat addition
D. Always increases the specific work output
Options:
1) A and D only
2) B and D only
3) A, C and D only
4) A, B, C and D
Correct Answer: A, B, C and D
QID : 813 - The amount of heat required to raise the temperature of 1 kg of water from 0°C to the saturation temperature Ts °C at a given constant pressure is defined as _____.
Options:
1) Superheat
2) Entropy
3) Latent heat
4) Sensible heat
Correct Answer: Sensible heat
QID : 814 - The enthalpy of steam is defined as _____.
Options:
1) Difference of internal energy and product of pressure and volume.
2) Product of internal energy and pressure.
3) Sum of internal energy and product of pressure and volume.
4) Amount of heat change divided by the absolute temperature.
Correct Answer: Sum of internal energy and product of pressure and volume.
QID : 815 - What are the advantages of water tube boilers over fire tube boilers?
A. Steam at higher pressures can be produced.
B. More effective heat transfer.
C. Sediment deposition is more.
Options:
1) A only
2) A and C only
3) A, B and C
4) A and B only
Correct Answer: A and B only
QID : 816 - What is the state, in which none of the properties of the system change with time, known as?
Options:
1) Unsteady state
2) Steady state
3) Dynamic
4) Quasistatic
Correct Answer: Steady state
QID : 817 - The rate of heat transfer across any plane normal to the x-direction is proportional to the wall area and the temperature gradient in the x-direction. This statement is also referred to as _____.
Options:
1) Second Law of Thermodynamics
2) Kelvin's Law
3) Third Law of Thermodynamics
4) Fourier's Law
Correct Answer: Fourier's Law
QID : 818 - The critical temperature of a pure substance is defined as _____
Options:
1) The minimum temperature at which solid and liquid phases can coexist in equilibrium.
2) The maximum temperature at which solid and liquid phases can coexist in equilibrium.
3) The minimum temperature at which vapour and liquid phases can coexist in equilibrium.
4) The maximum temperature at which vapour and liquid phases can coexist in equilibrium.
Correct Answer: The maximum temperature at which vapour and liquid phases can coexist in equilibrium.
QID : 819 - Which of the following is the correct expression for the maximum thermal efficiency (η) of a system undergoing a reversible power cycle while operating between thermal reservoirs at temperatures Tc and Th
Options:
1) η = Tc/Th
2) η = Th/Tc-1
3) η = 1-Tc/Th
4) η = 1
Correct Answer: η = 1-Tc/Th
QID : 820 - In actual refrigeration systems, the compressor handles vapour only. What is this process commonly referred to as _____.
Options:
1) Gas compression
2) Phase compression
3) Dry compression
4) Wet compression
Correct Answer: Dry compression
QID : 821 - Property of a fluid at zero temperature is referred to as _____.
Options:
1) Stagnation property
2) Standard property
3) Simple property
4) None of these
Correct Answer: Stagnation property
QID : 822 - The increase in pressure _____.
Options:
1) lowers the boiling point of a liquid
2) raises the boiling point of a liquid
3) does not affect the boiling point of a liquid
4) reduces its volume
Correct Answer: raises the boiling point of a liquid
QID : 823 - The overall efficiency of thermal power plant is _____.
Options:
1) Boiler efficiency, turbine efficiency and generator efficiency
2) Boiler efficiency, turbine efficiency, generator efficiency and gas cycle efficiency
3) Carnot cycle efficiency
4) Regenerative cycle efficiency
Correct Answer: Boiler efficiency, turbine efficiency and generator efficiency
QID : 824 - Heat transfer by radiation mainly depends upon _____.
Options:
1) its temperature
2) nature of the body
3) kind and extent of its surface
4) All optons are correct
Correct Answer: All optons are correct
QID : 825 - Thermal diffusivity is _____.
Options:
1) a dimensionless parameter
2) function of temperature
3) used as mathematical model
4) a physical property of the material
Correct Answer: a physical property of the material
QID : 826 - Condensing temperature in a refrigerator is the temperature _____.
Options:
1) of cooling medium
2) of freezing zone
3) of evaporator
4) at which refrigerant gas becomes liquid
Correct Answer: at which refrigerant gas becomes liquid
QID : 827 - With an increase in the thickness of insulation around a circular pipe, heat loss to surroundings due to _____.
Options:
1) convection increases, where as due to conduction decreases
2) convection decreases, where as due to conduction increases
3) both convection and conduction decreases
4) both convection and conduction increases
Correct Answer: convection increases, where as due to conduction decreases
QID : 828 - For air with a relative humidity of 80% _____.
Options:
1) dry bulb temperature is less than the wet bulb temperature
2) dew point temperature is less than wet bulb temperature
3) dew point and wet bulb temperatures are equal
4) dry bulb and dew point temperatures are equal
Correct Answer: dew point temperature is less than wet bulb temperature
QID : 829 - If a mass of moist air in an airtight vessel is heated to a higher temperature, then _____.
Options:
1) specific humidity of the air increases
2) specific humidity of the air decreases
3) relative humidity of the air increases
4) relative humidity of the air decreases
Correct Answer: relative humidity of the air decreases
QID : 830 - In a vapour compression refrigeration system, liquid to suction heat exchanger is used to _____.
Options:
1) keep the COP constant
2) prevent the liquid refrigerant from entering the compressor
3) sub-cool the liquid refrigerant leaving the condenser
4) sub-cool the vapour refrigerant from the evaporator
Correct Answer: sub-cool the liquid refrigerant leaving the condenser
QID : 831 - A right-circular cylinder open at top is filled with water and rotated about its vertical axis at such speed that half the water spills out. What is the value of pressure at centre of the bottom?
Options:
1) One half its value when cylinder was full
2) One fourth its value when cylinder was full
3) Zero
4) Insufficient data
Correct Answer: Zero
QID : 832 - At a point on a streamline, the velocity is 3 m/sec and the radius of curvature is 9 m. If the rate of increase of velocity along the streamline at this point is 1/3 m/sec/m, then the total acceleration at this point would be _____.
Options:
1) 1 m/sec2
2) 3 m/sec2
3) 1/3 m/sec2
4) √2 m/sec2
Correct Answer: √2 m/sec2
QID : 833 - Which of the following statements is correct regarding an impulse turbine?
Options:
1) The steam is initially compressed in a nozzle from low pressure to high pressure.
2) The steam is initially expanded in a nozzle from low pressure to high pressure.
3) The steam is initially compressed in a nozzle from high pressure to low pressure.
4) The steam is initially expanded in a nozzle from high pressure to low pressure.
Correct Answer: The steam is initially expanded in a nozzle from high pressure to low pressure.
QID : 834 - A draft tube is used with _____.
Options:
1) impulse turbine
2) Pelton wheel turbine
3) reaction turbines
4) axial turbine pumps
Correct Answer: reaction turbines
QID : 835 - For Newtonian fluid behaviour, the shear stress exerted by the fluid is equal to the _____.
Options:
1) Fluid viscosity divided by the velocity gradient parallel to the direction of shear.
2) Fluid viscosity divided by the velocity gradient perpendicular to the direction of shear.
3) Product of the fluid viscosity and the velocity gradient parallel to the direction of shear.
4) Product of the fluid viscosity and the velocity gradient perpendicular to the direction of shear.
Correct Answer: Product of the fluid viscosity and the velocity gradient perpendicular to the direction of shear.
QID : 836 - Which of the following are the advantages of impulse turbine over reaction turbines ?
A. Occupies less space per unit power.
B. Compounding is not necessary for speed reduction as the rotor speeds are usually low.
C. Suitable for high power generation.
Options:
1) B and C only
2) A only
3) C only
4) A and C only
Correct Answer: B and C only
QID : 837 - The compressors used in a gas turbine are typically of which type?
Options:
1) Centrifugal
2) Centripetal
3) Reciprocating
4) Axial
Correct Answer: Reciprocating
QID : 838 - Which turbine is also called as the propeller turbine?
Options:
1) Kaplan turbine
2) Francis turbine
3) Pelton wheel
4) Thompson turbine
Correct Answer: Kaplan turbine
QID : 839 - According to Bernoulli's principle in fluid dynamics, for inviscid flow, increase in speed of fluid leads to which of the following?
Options:
1) Increase in pressure and/or increase in fluid's potential energy
2) Decrease in pressure and/or increase in fluid's potential energy
3) Increase in pressure and/or decrease in fluid's potential energy
4) Decrease in pressure and/or decrease in fluid's potential energy
Correct Answer: Decrease in pressure and/or decrease in fluid's potential energy
QID : 840 - The material commonly used for air craft gas turbine is _____.
Options:
1) stainless steel
2) high alloy steel
3) duralumin
4) titanium
Correct Answer: duralumin
