SSC JE 11 Oct 2023 PAPER I Mechanical Part 7

Q.51 _______ is a metalworking process which is an example of forging.

1. Extrusion
2. Welding
3. Upsetting
4. Casting

Correct Option: 3

Q.52 In an I.C. engine, when the primary circuit in the coil ignition system breaks, the voltage produced across the secondary terminal is in the range of _______.

1. 2000 V to 5000 V
2. 80 V to 120 V
3. 800 V to 1200 V
4. 8000 V to 12,000 V

Correct Option: 4

Q.53 The friction experienced by the body when the body tends to move is known as:

1. dynamic friction
2. rolling friction
3. static friction
4. sliding friction

Correct Option: 3

SSC JE 11 Oct 2023 PAPER I Mechanical Part 7

Q.54 If the specific weight of a fluid is 19620 N/m3, then what will be its specific volume in m3/kg? (Take g = 9.81 m/sec2)

1. 5 ×10-3
2. 0.5 ×10 -3
3. 5 ×10-5
4. 0.5 ×10 -5

Correct Option: 2

Q.55 The function of condenser in refrigeration cooling system is _________.

1. to convert liquid refrigerant into vapour refrigerant
2. to reject heat out of the system
3. to give heat into the system
4. to give external work to the system

Correct Option: 2

Q.56 Vapour pressure is primarily associated with which phenomenon?

1. Capillarity
2. Cavitation
3. Surging
4. Water hammering

Correct Option: 2

Q.57 In an ammonia vapour compression system, the pressure in the evaporator is 2 bar. Ammonia at exit is 0.85 dry and at entry its dryness fraction is 0.19. During compression, the work done per kg of ammonia is 150 kJ. The latent heat and specific volume at 2 bar are 1325 kJ/kg and 0.58 m3 /kg, respectively. What will be its C.O.P?

1. 3.82
2. 6.74
3. 5.83
4. 4.34

Correct Option: 3

SSC JE 11 Oct 2023 PAPER I Mechanical Part 7

Q.58 Which of the following statements is true about a four-stroke engine in comparison to a two-stroke engine?

1. Thermal efficiency and part-load efficiency of a four-stroke engine are better than those of a two-stroke engine.
2. A four-stroke engine only uses the diesel cycle, while a two-stroke engine only uses the Otto cycle.
3. Volumetric efficiency of a four-stroke engine is comparatively low, due to less power output.
4. Owing to one power stroke in two revolutions, a lighter flywheel is required.

Correct Option: 1

Q.59 The cyclic integral of Q/T for a reversible cycle is equal to zero. This statement is known as _________.

1. the principle of Carathéodory
2. Clausius theorem
3. Rankine theorem
4. Carnot theorem

Correct Option: 2

Q.60 The mass flow is same at inlet and outlet in case of ___________.

1. non-steady flow process
2. isolated system
3. steady flow process
4. closed system

Correct Option: 3

Q.61 For hydraulic turbines, the ratio of overall efficiency and mechanical efficiency is called _________ .

1. volumetric efficiency
2. hydraulic efficiency
3. frictional power
4. cannot be predicted

Correct Option: 2

SSC JE 11 Oct 2023 PAPER I Mechanical Part 7

Q.62 In the thermodynamic system, the primary driving force for mass transfer is __________.

1. pressure difference
2. concentration difference
3. temperature difference
4. mass difference

Correct Option: 2

Q.63 In a steam boiler, the actual evaporation is 8 kg of steam per kg of fuel burnt. The heat supplied per kg of water is 2500 kJ/kg. Higher calorific value of fuel is 25,000 kJ/kg. What is the boiler efficiency?

1. 0.10
2. 0.80
3. 0.25
4. 0.75

Correct Option: 2

Q.64 Due to the refinement of grains, mechanical properties such as toughness, ductility, elongation and reduction in the area are improved in ___________ process

1. Forming
2. Hot working
3. Joining
4. Cold working

Correct Option: 2

SSC JE 11 Oct 2023 PAPER I Mechanical Part 7

Q.65 Which of the following statements is correct about a working engine?

1. Operation of the flywheel is continuous, whereas operation of the governor is more or less intermittent.
2. Operation of the governor is continuous, whereas operation of the flywheel is more or less intermittent.
3. Operation of both the flywheel and the governor is continuous.
4. Operation of both the flywheel and the governor is intermittent.

Correct Option: 1

Q.66 A piezometer is connected to a point in a pipe to measure the pressure of water flowing through it. If the piezometer reads 0.4 m, what will be the gauge pressure at that point?Take atmospheric pressure = 101325 pascals and g = 10 m/s2 .

1. 4000 pascals
2. 105325 pascals
3. 40 kilopascals
4. 97325 pascals

Correct Option: 1

Q.67 Under steady state operation of a cone clutch, if semi-cone angle (α) decreases then _____________ .

1. the torque produced by clutch decreases
2. does not affect the axial force
3. the torque produced by clutch increases
4. the axial force increases

Correct Option: 3

Q.68 The air pre-heater increases the temperature of ___________ before it/they enter(s) the furnace.

1. flue gases
2. fuel
3. air
4. feedwater

Correct Option: 3

SSC JE 11 Oct 2023 PAPER I Mechanical Part 7

Q.69 What is the function of the transfer port inside the engine?

1. It is the port through which the engine gets the fuel.
2. It is used to transfer unburnt fuel to the exhaust port.
3. It is the port through which scavenging of the gases takes place.
4. It is used to move charge from the crankcase to the cylinder head portion.

Correct Option: 4

Q.70 The following Temperature – Entropy diagram represents a Refrigeration system operates on the reversed Carnot cycle. The higher temperature of the refrigerant in the system is 35°C and the lower temperature is -15°C. What will be the C.O.P?

1. 2.75
2. 5.16
3. 4.82
4. 3.45

Correct Option: 2

Q.71 If the mechanical efficiency and hydraulic efficiency of a turbine are 60% and 70%, respectively, then what will be the overall efficiency of the turbine?

1. 70%
2. 60%
3. 42%
4. 65%

Correct Option: 3

Q.73 Which of the following is NOT a component of the water-cooling system with radiator?

1. Thermostat
2. Fan
3. Condenser
4. Centrifugal pump

Correct Option: 3

Q.74 Choose the correct option related to lathe turning operation.

1. Both tool and work piece will rotate
2. Work piece will rotate
3. Tool will rotate
4. Both tool and work piece will not rotate

Correct Option: 2

SSC JE 11 Oct 2023 PAPER I Mechanical Part 7

Q.75 A heat engine operates between a source at 600 K and a sink at 300 K. What is the maximum possible efficiency of the engine according to the Kelvin-Planck statement of the second law of thermodynamics?

1. 33.3%
2. 50%
3. 67%
4. 25%

Correct Option: 2

SSC JE 11 Oct 2023 PAPER I Mechanical Part 7