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.

251.

When is artificial draught preferred?

A. when quick evacuation of flue gases is required
B. when we choose large power plant systems
C. when draught produced by chimney is not sufficient
D. when there are many components inside the boiler
Answer» D. when there are many components inside the boiler
252.

Which of the following given below as the affect on amount natural draught?

A. boiler operation
B. size of the furnace
C. grade of the fuel
D. dust content in the fuel is used
Answer» B. size of the furnace
253.

By what is natural draught produced?

A. air duct
B. chimney
C. locomotive exhaust
D. air blower
Answer» C. locomotive exhaust
254.

Why boiler draught is most essential part of the thermal plants?

A. serves combustion by supplying ample amount of air
B. helps in maintaining air ventilation
C. required to maintain constant air flow
D. stabilizes the boiler system
Answer» D. stabilizes the boiler system
255.

Which is the correct formula of total draught loss?

A. ht = hv + hb + hc + hcd
B. ht = hv + hb – hc + hcd
C. ht = hv – hb + hc + hcd
D. ht = hv – hb – hc – hcd
Answer» B. ht = hv + hb – hc + hcd
256.

Which of the following boilers has the highest heat transfer capacity?

A. subcritical boiler
B. critical boiler
C. forced circulation boiler
D. supercritical boiler
Answer» E.
257.

What is the major difficulty of the La-Mont boiler?

A. unstable water circulation
B. deposition of salts
C. overheating of the components
D. boiler working is slow
Answer» C. overheating of the components
258.

What is feature of the Loffler boilers?

A. evaporating water by super heated steam
B. provide better efficiency by re-circulating gas coming out of turbine
C. produce better steam quality by heating the boiler furnace above critical degrees
D. eliminate the extra components used
Answer» B. provide better efficiency by re-circulating gas coming out of turbine
259.

Why are salts deposited on the evaporator drum?

A. due to continuous circulation of water
B. due to usage of hard water containing calcium content
C. due to circulation of impure water
D. due to the chemicals added in water
Answer» D. due to the chemicals added in water
260.

Which is the most recent economical method of power generation from boilers?

A. natural circulation boiler
B. fire tube boiler
C. forced circulation
D. super critical boiler
Answer» E.
261.

Which type of circulation is incurred in Schmidt-Hartmann boiler?

A. natural circulation
B. positive forced circulation
C. forced circulation
D. once-through circulation
Answer» B. positive forced circulation
262.

What is used to heat the feed water which is used for recirculation through tubes?

A. condenser
B. pre-heater
C. economizer
D. water clarifier
Answer» D. water clarifier
263.

How many circuits are there in the Schmidt-Hartmann boiler?

A. 3
B. 2
C. 4
D. 6
Answer» C. 4
264.

Which boiler is most successful boiler in the gas turbine industries?

A. because it has greater flexibility
B. it is easy to control, it’s fully automatic
C. it has higher thermal efficiency of all
D. can increase heat transfer without changing its size
Answer» E.
265.

What type of boiler is a Velox boiler?

A. forced circulation boiler
B. natural circulation boiler
C. positively forced circulation boiler
D. once- through boiler
Answer» B. natural circulation boiler
266.

Where is water steam separator drum located in Lamont boiler?

A. inside of the boiler
B. right above the furnace
C. before the feed water pump
D. outside of boiler
Answer» E.
267.

Which of the given boilers velocity of flue gases is greater than velocity of sound?

A. benson boiler
B. la-mont boiler
C. schmidt-hartmann boiler
D. velox boiler
Answer» E.
268.

What is the temperature at which the steam boilers are capable to withstand?

A. 200oc
B. 280oc
C. 540oc
D. 358oc
Answer» D. 358oc
269.

How can be the plant efficiency of steam power plant is increased?

A. by using high pressure and high temperature steam
B. by equipping ash and flue gas clearance system
C. by maintaining the boiler on daily basis by cleaning the soot and combustion products
D. by using better and efficient type of fuel for combustion
Answer» B. by equipping ash and flue gas clearance system
270.

In what is water in high pressure boiler circulated through?

A. conduits
B. cove
C. channel
D. tubes
Answer» E.
271.

What is needed to be increased to increase the heat transfer rate in the boiler?

A. gas velocities
B. fuel input
C. water velocities
D. air supply
Answer» D. air supply
272.

Why single boiler unit per turbine is equipped commonly?

A. for better turbine control
B. to deduce the costs
C. for overcoming losses of power
D. to improve the efficiency
Answer» B. to deduce the costs
273.

Why starting valve is closed and valve 2 is opened while taking boiler on range in Benson boiler?

A. avoid excessive heating of tube
B. to maintain the constant flow of water
C. to avoid pressure built up in tubes
D. to avoid pipe leakages at joints
Answer» B. to maintain the constant flow of water
274.

What is the major disadvantage of the Benson boilers?

A. boiler is big in size
B. has large storage capacity
C. deposition of salts
D. bubble formation
Answer» D. bubble formation
275.

What is the function of boiler?

A. to burn the fuel in a confined closed system with the supply of air
B. to generate steam at varying pressure
C. to generate steam at constant pressure
D. to produce flue gases by burning fuel at a given pressure
Answer» D. to produce flue gases by burning fuel at a given pressure
276.

What is the capacity of Benson boiler?

A. 180 tonnes/hr & above
B. 150 tonnes/hr & above
C. 250 tonnes/hr & above
D. 300 tonnes/hr & above
Answer» C. 250 tonnes/hr & above
277.

What type of boiler is a Benson boiler?

A. super critical boiler
B. fire tube boiler
C. natural circulation boiler
D. over-through boiler
Answer» B. fire tube boiler
278.

What is the main disadvantage of Lamont boiler?

A. less flexible in design
B. low heat transfer rate
C. formation of bubbles
D. low steam generation capacity
Answer» D. low steam generation capacity
279.

What type of steam is generated by evaporator tube of Lamont boiler?

A. saturated steam
B. unsaturated steam
C. superheated steam
D. flash steam
Answer» B. unsaturated steam
280.

What is the pressure range between which Lamont boilers operates?

A. 80-120bar
B. 120-160bar
C. 180-360bar
D. 450-560bar
Answer» C. 180-360bar
281.

Through which does the even circulation of feed water is possible in Lamont boiler?

A. nozzles
B. water trough
C. feed pump
D. hose
Answer» B. water trough
282.

What is called as the heart of the Lamont boiler?

A. water drum
B. centrifugal pump
C. furnace
D. blower
Answer» C. furnace
283.

What type of boiler is a Lamont boiler?

A. forced circulation
B. natural circulation
C. over-through
D. positive forced circulation
Answer» B. natural circulation
284.

Which type of boiler is it when the furnace is placed in the region of boiling water?

A. internally fired boiler
B. externally fired boiler
C. babcock-wilcox boiler
D. stirling boiler
Answer» B. externally fired boiler
285.

In what form are the boiler’s tube arrange in Lamont boiler?

A. parallel in vertical
B. inclined vertically
C. parallel in horizontal
D. horizontally inclined
Answer» D. horizontally inclined
286.

Compounding is used for _________ power applications.

A. low
B. high
C. medium
D. none of the mentioned
Answer» C. medium
287.

Reaction turbine is also called as _________

A. impulse turbine
B. curtis wheel
C. parsons turbine
D. none of the mentioned
Answer» D. none of the mentioned
288.

A velocity compounded impulse turbine is also called as __________

A. curtis wheel
B. pressure compounded
C. curtis wheel & pressure compounded
D. none of the mentioned
Answer» B. pressure compounded
289.

In velocity compounded turbines flow passage is from ____________

A. moving blades to fixed nozzles
B. fixed nozzles to moving blades
C. fixed blades to moving nozzles
D. none of the mentioned
Answer» E.
290.

Compounding __________ efficiency at low speed.

A. decrease
B. increase
C. maximizes
D. none of the mentioned
Answer» C. maximizes
291.

A turbine having alternate blades and nozzles is called as _______________

A. impulse turbine
B. reaction turbine
C. impulse & reaction turbine
D. none of the mentioned
Answer» B. reaction turbine
292.

Multi stage arrangement of turbines is called as __________

A. impulse turbine
B. reaction turbine
C. compounding
D. none of the mentioned
Answer» D. none of the mentioned
293.

In the equation Cd=1/K(0.5) what does K mean ?

A. pressure drop inside the nozzle
B. mass flow rate
C. flow resistance
D. none of the mentioned
Answer» D. none of the mentioned
294.

For sharp edge orifice, coefficient of discharge lies between ___________

A. 0.61 – 0.64
B. 0.87 – 0.89
C. 0.50 – 0.61
D. none of the mentioned
Answer» B. 0.87 – 0.89
295.

Coefficient of discharge is _____________

A. directly proportional to coefficient of discharge
B. inversely proportional to square of the coefficient of discharge
C. inversely proportional to coefficient of discharge
D. directly proportional to square of coefficient of discharge
Answer» C. inversely proportional to coefficient of discharge
296.

Coefficient of discharge is the ____________

A. product of coefficient of velocity and coefficient of contraction
B. arithmetic sum of coefficient of velocity and coefficient of contraction
C. ratio of coefficient of velocity and coefficient of contraction
D. none of the mentioned
Answer» B. arithmetic sum of coefficient of velocity and coefficient of contraction
297.

Unit of flow resistance is _________

A. n/m2
B. m2/n
C. kn/kg
D. no unit
Answer» E.
298.

Coefficient of discharge is used to measure ___________

A. none of the mentioned
B. pressure exerted by the nozzle on the fluid
C. flow rate allowed by the nozzle
D. resistance offered by the nozzle
Answer» E.
299.

Coefficient of discharge is the __________ of Actual discharge to the theoretical discharge.

A. ratio
B. product
C. sum
D. none
Answer» B. product
300.

When steam is transported dryness fraction _________

A. increases
B. decreases
C. remains constant
D. none of the mentioned
Answer» C. remains constant