GATE Past Year Questions: Power Plant Engineering | Thermodynamics - Mechanical Engineering PDF Download

Maximum temperature of steam in kelvin

Heat transfer rate in kJ/hr

Heat transfer area in meter²

Steam output in kg/hr

2000

2149

186

1649

Blow off cock

Feed pump

Economizer

Super heater

Equal to 1.0

Greater than 1.0

Less than 1.0

Independent of inlet conditions

Divergent and convergent respectively

Both divergent

Both convergent

Convergent and divergent respectively

50

40

60

75

Thermal efficiency increases

Steam consumption decreases

Steam dryness after expansion increases

All of the above

Reversibly at constant volume

Reversibly at constant temperature

Reversibly at constant pressure and temperature

Reversibly at constant pressure

Scavenging process

Deaeration process

Exhaust process

Condensation process

Only the thermal efficiency

Only the specific power output

Both thermal efficiency and specific power output

Neither thermal efficiency nor specific power output

Saturated cycle

Superheated cycle

Reheat cycle

Regenerative cycle

Stirling cycle

Atkinson cycle

Ericson cycle

Brayton cycle

mh₁ – (h₂ – h₁)

h₁ – m(h₂ – h₁)

h₂ – m(h₂ – h₁)

mh₂ – (h₂ – h₁)

the enthalpy of main steam is higher for superheat cycle

the mean temperature of heat addition is higher for superheat cycle

the temperature of steam in the condenser is high

the quality of steam in the condenser is low

pressure inside the boiler increases

heat is added before steam enters the low pressure turbine

average temperature of heat addition in the boiler increases

total work delivered by the turbine increases

689.64 kJ/kg

794.66 kJ/kg

1009.72 kJ/kg

1312.00 kJ/kg

203.60

200.53

196.38

188.45

Both (A) and (R) are true and (R) is the correct reason for (A)

Both (A) and (R) are true but (R) is NOT the correct reason for (A)

Both (A) and (R) are false

(A) is false but (R) is true

Both (A) and (R) are true and (R) is the correct reason for (A)

Both (A) and (R) are true but (R) is NOT the correct reason for (A)

Both (A) and (R) are false

(A) is false but (R) is true

P and S

Q and S

P, R and S

P, Q, R and S

720 kJ/kg

2280 kJ/kg

1500 kJ/kg

3000 kJ/kg

3.60

0.36

0.06

0.01

500 and 900        

900 and 500

500 and 5400      

900 and 900

0.34

2.48

2.92

3.43

P and Q

R and S

Q and R

P and S

it increases the irreversibility by adding the liquid with higher energy content to the steam generator

heat is exchanged between the expanding fluid in the turbine and the compressed fluid before heat addition

the principle is similar to the principle of Stirling gas cycle

it is practically implemented by providing feed water heaters

Increasing the turbine inlet temperature

Decreasing the condenser pressure

Increasing the boiler pressure

Decreasing the boiler pressure

The fuel combustion temperature in a steam generator is lower than that in a gas turbine engine

Of the corrosive nature of high temperature steam on super heater tubes

The materials used for the gas turbine blades are not suitabie for the steam turbine blades

Unlike the gas turbine blades the steam turbine blades cannot be cooled

334

356

668

711

34%

39%

45%

30%

124 kJ

164 kJ

169 kJ

174 kJ

V_N cos 2α

V_N sin 2α

V_N cos (α/2)

different types of impulse stages

different types of reaction stages

a simple impulse stage, a velocity compounded impulse stage and reaction stage

a.velocity compounded impulse stage, a pressure compounded impulse stage and a reaction stage

Parsons

Curtis

Rateau

All of three

pressure compounded turbine

reaction turbine

velocity compounded turbine

radial flow turbine

both pressure and velocity decrease

pressure decreases but velocity increases

pressure remains constant, while velocity increases

pressure remains constant, while velocity decreases

an impulse turbine

a reaction turbine

a centrifugal compressor

an axial flow compressor

901.2

911.2

17072.5

17082.5