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.

351.

The vapour going to condenser is in temperature and in ammonia.

A. higher, less
B. higher, richer
C. lower, less
D. lower, richer
Answer» E.
352.

Which of the following condenses first?

A. ammonia vapour
B. water vapour
C. both condense at same temperature
D. none of the mentioned
Answer» C. both condense at same temperature
353.

In the aqua-ammonia absorption system,

A. water is the refrigerant and ammonia is the absorbent
B. ammonia is the refrigerant and water is the absorbent
C. both ammonia and water can be used as refrigerant or absorbent
D. none of the mentioned
Answer» C. both ammonia and water can be used as refrigerant or absorbent
354.

In absorption system, compressor in vapour compression cycle is replaced by absorber- generator assembly.

A. true
B. false
Answer» B. false
355.

In absorption refrigeration cycle, which of the following is used?

A. refrigerant
B. absorbent
C. both of the mentioned
D. none of the mentioned
Answer» D. none of the mentioned
356.

A condenser must and then the compressed refrigerant.

A. superheat, evaporate
B. desuperheat, evaporate
C. superheat, condense
D. desuperheat, condense
Answer» E.
357.

Which of the following is recommended in a refrigeration cycle?

A. superheating of vapour
B. subcooling of liquid
C. both of the mentioned
D. none of the mentioned
Answer» D. none of the mentioned
358.

One tonne of refrigeration is given as the rate of heat removal from surroundings equivalent to heat required for melting one tonne of ice in a day.

A. true
B. false
Answer» B. false
359.

The COP of cycle is given by(Q2=heat absorbed by evaporator and Wc=work done by compressor)

A. 1- (q2/wc)
B. 1- (wc/q2)
C. q2/wc
D. wc/q2
Answer» D. wc/q2
360.

In the expansion process, which of the following remains constant?

A. work done
B. heat supplied
C. internal energy
D. enthalpy
Answer» E.
361.

The evaporator produces the cooling or refrigerating effect.

A. true
B. false
Answer» B. false
362.

The evaporation process is a

A. constant volume reversible process
B. constant pressure reversible process
C. adiabatic throttling process
D. reversible adiabatic process
Answer» C. adiabatic throttling process
363.

The expansion process is

A. isentropic
B. reversible
C. adiabatic
D. all of the mentioned
Answer» D. all of the mentioned
364.

Why is wet compression not preferred?

A. the liquid refrigerant can be trapped in the head of cylinder
B. this may damage the valves or cylinder head
C. liquid refrigerant can wash away the lubricating oil thus accelerating wear
D. all of the mentioned
Answer» E.
365.

Wet compression is preferred over dry compression.

A. true
B. false
Answer» C.
366.

Compression can be

A. dry compression
B. wet compression
C. both of the mentioned
D. none of the mentioned
Answer» D. none of the mentioned
367.

Which of the following operations occur in a vapour refrigeration cycle?

A. compression
B. cooling and condensing
C. expansion and evaporation
D. all of the mentioned
Answer» E.
368.

In how many categories heat exchangers are classified on the basis of physical state of heat exchanging fluids?

A. 1
B. 2
C. 3
D. 4
Answer» C. 3
369.

In how many categories heat exchangers are classified on the basis of direction of flow of fluids?

A. 4 categories
B. 3 categories
C. 2 categories
D. 1 categories
Answer» C. 2 categories
370.

Which of the following is not an example of recuperators type heat exchanger?

A. automobile radiators
B. condensers
C. chemical factories
D. oil heaters for an aero plane
Answer» D. oil heaters for an aero plane
371.

Which type of flow arrangement is this?

A. counter flow
B. parallel flow
C. regenerator
D. shell and tube
Answer» C. regenerator
372.

The energy transfer between the hot fluid and cold fluids is brought about by their complete physical mixing in

A. direct contact heat exchanger
B. regenerators
C. recuperators
D. boilers
Answer» B. regenerators
373.

Based upon the nature of heat exchange process, the heat exchangers are classified into how many categories

A. 1
B. 2
C. 3
D. 4
Answer» D. 4
374.

Heat exchangers are classified into how many categories?

A. 1
B. 2
C. 3
D. 4
Answer» E.
375.

Pass-out turbines are used in which of these cases?

A. relatively high back pressure
B. small heating requirement
C. only relatively low back pressure
D. both relatively high back pressure and small heating requirement
Answer» E.
376.

Which of these is not an application of back pressure turbine?

A. desalination of sea water
B. filtration of water
C. process industries
D. petrochemical installations
Answer» C. process industries
377.

A turbine comprising of fixed blades and moving nozzles is called as reaction turbines.

A. true
B. false
Answer» B. false
378.

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
379.

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.
380.

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
381.

Compounding efficiency at low speed.

A. decrease
B. increase
C. maximizes
D. none of the mentioned
Answer» C. maximizes
382.

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
383.

When steam reaches turbine blades the type of force responsible for moving turbine blades are

A. axial force
B. shear force
C. longitudinal force
D. none of the mentioned
Answer» B. shear force
384.

Cross compound steam turbines are once used in

A. generation of electricity
B. marine ships
C. automobiles
D. none of the mentioned
Answer» C. automobiles
385.

Astern turbines are used in

A. power generation
B. marine purposes
C. aircraft
D. none of the mentioned
Answer» C. aircraft
386.

Impulse blades are in the shape of

A. rain drop
B. circular
C. half moon
D. none of the mentioned
Answer» D. none of the mentioned
387.

High pressure turbine is a Non-Condensing turbine due to

A. exhaust conditions
B. axial flow of the steam
C. pressure-velocity compounding
D. velocity compounding
Answer» B. axial flow of the steam
388.

Steam turbine is classified on basis of

A. type of blades
B. exhausting condition
C. type of steam flow
D. all of the mentioned
Answer» E.
389.

Non Condensing steam turbine can also be called as

A. extraction steam turbine
B. back pressure steam turbine
C. impulse steam turbine
D. none of the mentioned
Answer» C. impulse steam turbine
390.

Which turbines are employed for driving alternator at synchronous speed?

A. central station turbine
B. reheating turbine
C. extraction turbine
D. extraction induction turbine
Answer» B. reheating turbine
391.

Majority of the turbines are axial flow type.

A. true
B. false
Answer» B. false
392.

Which among the following fuels need excess amount of air for complete combustion?

A. natural fuels
B. liquid fuels
C. gaseous fuels
D. artificial solid fuels
Answer» E.
393.

Which liquid fuel has a wider composition than diesel and used in furnaces of oil fired boiler?

A. fuel oil
B. petrol
C. distillate
D. alcohol
Answer» B. petrol
394.

Which is the artificial liquid fuel obtained by fermentation process?

A. fuel oil
B. alcohol
C. distillate
D. kerosene
Answer» C. distillate
395.

Which of the following is not a type of steam turbine?

A. impulse turbine
B. reaction turbine
C. pelton wheel turbine
D. axial flow type turbine
Answer» D. axial flow type turbine
396.

Which fuel is slightly heavier than kerosene and is produced in petroleum fractions?

A. diesel
B. crude oil
C. gasoline
D. distillate
Answer» E.
397.

Which fuel has higher thermodynamic efficiency in liquid fuels?

A. diesel
B. petrol
C. kerosene
D. lpg
Answer» B. petrol
398.

Which fuel is heavier than petrol but less volatile and it is commonly used as domestic fuel?

A. diesel
B. distilled fuel
C. kerosene
D. alcohol
Answer» D. alcohol
399.

Name the process used to eliminate impurities present in crude oil?

A. distillation
B. filtration
C. sedimentation
D. coagulation
Answer» B. filtration
400.

In what forms are liquid fuels available in nature?

A. light distillate
B. petroleum spirit
C. petroleum naphtha
D. crude petroleum
Answer» E.