Explore topic-wise MCQs in Mechanical Engineering.

This section includes 463 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.

151.

In the mercury steam cycle, the mercury cycle is called?

A. bottoming cycle
B. middle cycle
C. topping cycle
D. none of the mentioned
Answer» D. none of the mentioned
152.

The mercury steam cycle represents how many coupled Rankine cycles?

A. 1
B. 2
C. 3
D. 4
Answer» C. 3
153.

By using combined cycle steam and gas power plant _________

A. specific fuel consumption can be decreased
B. efficiency increased
C. specific fuel consumption can be decreased and efficiency increased
D. none of the mentioned
Answer» D. none of the mentioned
154.

Combination of two or more thermodynamic processes gives _________

A. decrease in efficiency
B. increase in efficiency
C. increases the temperature at exhaust
D. none of the mentioned
Answer» C. increases the temperature at exhaust
155.

What are turbo-compound engines?

A. turbines run at exhausts of otto and diesel cycles
B. combination of turbofan and turbojet engines
C. combination of turboprop and turbofan engines
D. none of the mentioned
Answer» B. combination of turbofan and turbojet engines
156.

Turbines that are run by exhaust gases are called _______

A. power recovery turbines
B. stepped turbines
C. turbo compounded engine
D. none of the mentioned
Answer» B. stepped turbines
157.

5. How many sections does waste heat recovery boiler have in steam generators?

A. 1
B. 2
C. 3
D. 4
Answer» D. 4
158.

. Due to the limits, upper efficiency of steam turbines is fixed to _________

A. 10-15%
B. 25-45%
C. 20-40%
D. 35-45%
Answer» E.
159.

Which of the following waste types are not suitable for co-combustion in cement kilns?

A. chlorine
B. hydrogen
C. calcium
D. carbonate
Answer» B. hydrogen
160.

Non-volatile heavy metals in kiln are fixed into __________

A. clinker’s crystalline structure
B. fumes
C. solid lump
D. slag
Answer» B. fumes
161.

What is the combustion temperature range in cement kiln incineration?

A. 1300-1600
B. 1350-1650
C. 1250-1450
D. 1235-1600
Answer» C. 1250-1450
162.

Which of the following industrial process uses waste as a fuel?

A. cement kilns
B. lead manufacturing
C. acid manufacturing
D. sulphur manufacturing
Answer» B. lead manufacturing
163.

Energy recovery is typically via production of __________

A. gas
B. heat
C. light
D. steam
Answer» E.
164.

The engines which are operating on gas power cycle are?

A. cyclic
B. non-cyclic
C. either cyclic or non-cyclic
D. none of the mentioned
Answer» D. none of the mentioned
165.

What is the importance of the freezing point of the working fluid in the vapour power cycle?

A. freezing point of working fluid should be below the room temperature
B. freezing point of working fluid should be above the room temperature
C. freezing point of working fluid should be equal to the room temperature
D. does not have any importance
Answer» B. freezing point of working fluid should be above the room temperature
166.

What is the specific heat of the ideal working fluid used in vapour power cycle?

A. should be constant
B. should be large
C. should be small
D. none of the mentioned
Answer» D. none of the mentioned
167.

Temperature of heat rejection in a condenser can be lowered by using?

A. lubricant
B. oil
C. refrigerant
D. diesel
Answer» D. diesel
168.

The use of which of the following becomes necessary during expansion of steam?

A. reheat
B. regeneration
C. refrigeration
D. superheat
Answer» B. regeneration
169.

What is the relation of the mean temperature of heat addition and cycle efficiency?

A. both are inversely proportional
B. both are directly proportional
C. both are independent of each other
D. none of the mentioned
Answer» C. both are independent of each other
170.

High moisture content is involved during expansion of steam because ___________

A. to ensure uniform heating
B. to ensure uniform cooling
C. to obtain a higher temperature of heat addition
D. to obtain a lower temperature of heat addition
Answer» D. to obtain a lower temperature of heat addition
171.

Addition of an infinitesimal amount of heat at the highest temperature is because ___________

A. to initiate reheating
B. to initiate regeneration
C. to initiate superheating
D. none of the mentioned
Answer» D. none of the mentioned
172.

Back pressure turbine is placed between ____________

A. turbine & pump
B. boiler & pump
C. turbine & heat exchanger
D. boiler & turbine
Answer» E.
173.

In condensing turbine what is the back pressure of the turbine?

A. very high
B. above atmospheric pressure
C. equal to atmospheric pressure
D. below atmospheric pressure
Answer» E.
174.

Reaction turbines are characterized by ___________

A. relatively low rpm and steam expension over nozzle
B. relatively high rpm and steam expension over nozzle
C. relatively low rpm and steam expension over rotor blades
D. relatively high rpm and steam expansion over rotor blades
Answer» D. relatively high rpm and steam expansion over rotor blades
175.

Which statement about reaction turbine is false?

A. steam does not expand in nozzle
B. blades acts like nozzles
C. steam expands as flows over the rotor blades
D. steam continuously losses its heat as flows over the rotor blades
Answer» E.
176.

Having two separate units for process heat and power is?

A. useful
B. useless
C. pollution reducing
D. none of the mentioned
Answer» C. pollution reducing
177.

Superficial steam turbines releases _______ CO2.

A. high
B. low
C. does not release
D. none of the mentioned
Answer» B. low
178.

Superficial steam turbines can be operated at ________

A. medium speeds
B. low speeds
C. high speeds
D. none of the mentioned
Answer» D. none of the mentioned
179.

Energy efficiency of superficial steam is _________

A. low
B. high
C. same as other steams
D. none of the mentioned
Answer» C. same as other steams
180.

Superficial steam power plants operate at _____ temperatures.

A. high
B. low
C. constant
D. none of the mentioned
Answer» B. low
181.

Steam turbines used in nuclear reactors use __________

A. superficial fluids
B. high pressure steam
C. specific heat
D. none of the mentioned
Answer» B. high pressure steam
182.

When steam pressure ________ it becomes superficial fluid.

A. decreases
B. increases
C. steam can not become superficial fluid
D. none of the mentioned
Answer» C. steam can not become superficial fluid
183.

_______ of electricity in United States is produced using steam turbine.

A. 88%
B. 50%
C. 100%
D. 77%
Answer» B. 50%
184.

A steam turbine with no nozzle is?

A. reaction turbine
B. impulse turbine
C. reaction & impulse turbines
D. none of the mentioned
Answer» B. impulse turbine
185.

Steam turbines may be classified according to ____________

A. number of stages
B. direction of steam flow
C. mode of steam action
D. all of the mentioned
Answer» E.
186.

If the critical pressure ratio for steam is 0.546, then the steam is initially ____________

A. wet
B. dry saturated
C. superheated
D. none of the mentioned
Answer» D. none of the mentioned
187.

A steam nozzle converts ____________

A. heat energy of steam into potential energy
B. potential energy into heat energy of steam
C. heat energy of steam into kinetic energy
D. kinetic energy into heat energy of steam
Answer» D. kinetic energy into heat energy of steam
188.

A stage, in reaction turbine, is represented by ____________

A. each row of blades
B. number of entries of steam
C. number of exits of steam
D. none of the mentioned
Answer» B. number of entries of steam
189.

In an impulse turbine, steam expands ____________

A. wholly in nozzle
B. partly in the nozzle and partly in blades
C. wholly in blades
D. none of the mentioned
Answer» B. partly in the nozzle and partly in blades
190.

The reheat factor depends upon ____________

A. exit pressure
B. turbine stage efficiency
C. initial pressure and superheat
D. all of the mentioned
Answer» E.
191.

The ratio of the isentropic heat drop to the heat supplied is called ____________

A. stage efficiency
B. reheat factor
C. internal efficiency
D. rankine efficiency
Answer» E.
192.

What is the critical pressure ratio for initially dry saturated steam?

A. 0.546
B. 0.577
C. 0.586
D. 0.578
Answer» C. 0.586
193.

In a reaction turbine, when steam flows through the fixed blades ____________

A. pressure decreases while velocity increases
B. pressure increases while velocity decreases
C. pressure and velocity both increases
D. pressure and velocity both decreases
Answer» B. pressure increases while velocity decreases
194.

What is the purpose of governing in steam turbines?

A. reheat the steam and improve its quality
B. maintain the speed of the turbine
C. reduce the effective heat drop
D. completely balance against end thrust
Answer» C. reduce the effective heat drop
195.

Curtis turbine is a ____________

A. pressure compounded turbine
B. velocity compounded turbine
C. simple reaction turbine
D. pressure-velocity compounded turbine
Answer» E.
196.

A binary vapour plant consists of ____________

A. mercury boiler
B. steam turbine
C. steam condenser
D. all of the mentioned
Answer» E.
197.

Steam turbines are used for ____________

A. electric power generation
B. large marine propulsion
C. direct drive of fans, compressors, pumps
D. all of the mentioned
Answer» E.
198.

The steam enters the nozzle at a ____________

A. low pressure and a low velocity
B. high pressure and a low velocity
C. low pressure and a high velocity
D. high pressure and a high velocity
Answer» E.
199.

The variation of steam pressure in the nozzle depends upon ____________

A. dryness fraction of steam
B. specific volume of steam
C. velocity of steam
D. all of the mentioned
Answer» E.
200.

The flow of steam is super-sonic ____________

A. in the convergent portion of the nozzle
B. at the entrance to the nozzle
C. at the throat of the nozzle
D. in the divergent portion of the nozzle
Answer» E.