# SSC JE 9 Oct 2023 PAPER I Mechanical Part 7

## SSC JE 9 Oct 2023 PAPER I Mechanical Part 7

SSC JE 9 Oct 2023 PAPER I Mechanical Part 7

Q.51 In aqua-ammonia absorption refrigeration system, incomplete rectification leads to accumulation of water in:

1. condenser
2. evaporator
3. heat exchanger
4. absorber

Correct Option: 1

Q.52 Which of the following is NOT an example of brittle material?

1. Aluminium
2. High carbon steel
3. Cast iron
4. Ceramic materials

Correct Option: 1

SSC JE 9 Oct 2023 PAPER I Mechanical Part 7

Q.53 Ammonia is NOT used in domestic refrigeration and comfort air-conditioning because:

1. lubricating oil is not soluble in ammonia at all
2. it is toxic and flammable
3. its heat transfer coefficient is very low
4. it is not soluble in water

Correct Option: 2

Q.54 The amount of water striking the runner of the reaction turbine is controlled by _____.

1. guide mechanism
2. draft tube
3. casing
4. spear arrangement

Correct Option: 1

Q.56 In actual air-conditioning applications for R-12 and R-22 refrigerant and operating at a condenser temperature of 40°C and an evaporator temperature of 5°C, the heat rejection factor is about:

1. 1.25
2. 1
3. 5.12
4. 2.15

Correct Option: 1

SSC JE 9 Oct 2023 PAPER I Mechanical Part 7

Q.57 If the temperature of ‘A’ is equal to the temperature of ‘B’ and ‘C’, then the temperature of ‘B’ will be equal to the temperature of ‘C’. This is known as:

1. Joule’s law
2. zeroth law of thermodynamics
3. law of thermal equilibrium
4. law of equality of temperature

Correct Option: 2

Q.58 What is the value of the density of water at 4°C?

1. 1 gm/cm3
2. 10 gm/cm3
3. 100 gm/cm3
4. 1000 gm/cm3

Correct Option: 1

Q.59 A circular opening, 3 m diameter, in a vertical side of a tank is closed by a disc of 3 m diameter which can rotate about a horizontal diameter and depth of centre of gravity from free surface is 4 m. What will be the total pressure on the disc?

1. 100 kN
2. 175.7 kN
3. 234.89 kN
4. 277.4 kN

Correct Option: 4

SSC JE 9 Oct 2023 PAPER I Mechanical Part 7

Q.60 A closed system undergoes a process in which the work done by the system is 100 J and the internal energy decreases by 50 J. According to the first law of thermodynamics, what is the amount of heat transferred into or out of the system?

1. −150 J
2. −50 J
3. 150 J
4. 50 J

Correct Option: 4

Q.61 What will be the atmospheric pressure at a location where the barometric reading is 750 mm Hg and the gravitational acceleration is g = 9.81 m/s2? Assume the density of mercury to be 13,600 kg/m3.

1. 100.06 kPa
2. 1000.6 Pa
3. 10.006 kPa
4. 100.06 Pa

Correct Option: 1

Q.62 What is the unit of measurement of actual evaporation in steam boilers?

1. m3/kg
2. kg
3. kg fuel burnt / kg water evaporated
4. kg water evaporated / kg fuel burnt

Correct Option: 4

SSC JE 9 Oct 2023 PAPER I Mechanical Part 7

Q.64 Which of the following statements about equilibrium is correct?

1. Summation of all the forces acting in one direction must be zero.
2. Summation of all the forces acting in all the possible directions must be zero.
3. Summation of all the forces acting in all the possible directions must be non-zero.
4. Summation of all the forces acting in one direction must not be zero.

Correct Option: 2

SSC JE 9 Oct 2023 PAPER I Mechanical Part 7

Q.65 Which of the following pressure measurement devices consists of a hollow metal tube bent like a hook whose end is closed and connected to a dial indicator needle?

1. Bourdon tube
2. Strain-gauge pressure transducers
3. Piezoelectric transducers
4. Pressure transducers

Correct Option: 1

Q.66 In a Carnot cycle, _______.

1. all processes are reversible
2. only adiabatic processes are reversible
3. all processes are irreversible
4. only isothermal processes are reversible

Correct Option: 1

SSC JE 9 Oct 2023 PAPER I Mechanical Part 7

Q.67 In Bell-Coleman Cycle, the pressure at the end of isentropic compression is same as:

1. the pressure at the end of isentropic expansion
2. the pressure at the start of isentropic expansion
3. the pressure at the start of isentropic compression
4. the pressure in constant pressure expansion

Correct Option: 2

Q.68 Which of the following ideal gas processes has the highest polytropic index?

1. Isochoric process
2. Isobaric process
3. Isothermal process
4. Isentropic process

Correct Option: 1

Q.69 The bent tube of a Bourdon tube pressure gauge will change its shape when exposed to variations of _______.

1. voltage
2. resistance
3. displacement
4. pressure

Correct Option: 4

SSC JE 9 Oct 2023 PAPER I Mechanical Part 7

Q.70 Which one of the following is correct statement about Blade cross sectional fluid flow area from inlet to outlet of a turbine?

1. Constant for reaction turbine and converging for impulse turbine
2. Constant for impulse turbine and converging for reaction turbine
3. Constant for reaction turbine and diverging for impulse turbine
4. Constant for impulse turbine and diverging for reaction turbine

Correct Option: 2

Q.71 The pressure intensity at a point in a fluid is given as 3.924 N/cm2. What will be the corresponding height of fluid when the fluid is water?

1. 2.5 m of water
2. 6 m of water
3. 3.5 m of water
4. 4 m of water

Correct Option: 4

SSC JE 9 Oct 2023 PAPER I Mechanical Part 7

Q.73 The ratio of the actual mass flow rate to that due to isentropic expansion in the steam nozzle is known as _________.

1. critical pressure ratio
2. coefficient of discharge
3. Mach number
4. nozzle efficiency

Correct Option: 2

SSC JE 9 Oct 2023 PAPER I Mechanical Part 7

Q.74 A thermometer works on the principle of ____________.

1. 3rd law of thermodynamics
2. Joule’s law
3. 2nd law of thermodynamics
4. Zeroth law of thermodynamics

Correct Option: 4

SSC JE 9 Oct 2023 PAPER I Mechanical Part 7

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