3B2 Power Engineer Exam Practice Questions With Complete Solutions

3B2 Power Engineer Exam Practice Questions With Complete Solutions



The disadvantages of a gas turbine are:

1. High cost of manufacture

2. High levels of noise pollution are produced

3. Low thermal efficiency

4. Requires many auxiliaries to be efficient



A. 1, 2, 3

B. 1, 3, 4

C. 2, 3, 4

D. 1, 2, 4

E. 1, 2, 3, 4 - (ANSWER)E



The most common process method of refrigeration is:

Select one:

A. Absorption

B. Lithium bromide

C. Water vapor

D. Vapor compression or mechanical

E. Ammonia compression system - (ANSWER)D



To facilitate the removal of moisture and oil from the compressed air, a/an _____ is installed.

Select one:

A. Intercooler

B. Oil separator

C. Unloader

D. Expansion tank

E. Aftercooler - (ANSWER)E

,3B2 Power Engineer Exam Practice Questions With Complete Solutions



In a two-stage refrigeration system, the 1st stage compressor is also known as a _____ compressor.

Select one:

A. Booster

B. Standby

C. Low volume

D. Extraction

E. Refrigerant - (ANSWER)A



In the rotary vane compressor:

Select one:

A. Vanes close to the central hub by centrifugal force

B. There is a rotor in the exact center of the casing

C. Refrigerant is trapped between the roller and the decreasing volume of the eccentric casing

D. The rotor oscillates

E. The vanes move in the rotor - (ANSWER)E



In a gas turbine, there are fewer turbine stages than compressor stages because:

Select one:

A. Energy can be extracted more efficiently in the turbine

B. Turbine blades are bigger so require fewer

C. Higher exhaust temperatures can be tolerated

D. The hot gases occupy more volume

E. Hot exhaust gases are required for the HRSG's - (ANSWER)A



Pressure limiting devices of refrigeration systems shall be connected:

Select one:

A. Between the compressor and the stop valve on the suction side

B. To a blowdown tank

,3B2 Power Engineer Exam Practice Questions With Complete Solutions



C. Between the inlet of the condenser and the outlet of the receiver

D. Between the compressor and the stop valve on the discharge side

E. To the receiver outlet - (ANSWER)D



The warm-up time required of a turbine is dependant on:

Select one:

A. How quickly the turbine is required

B. The manufacturer's instructions

C. The size of the turbine

D. The type of turbine

E. Whether the steam is dry or wet - (ANSWER)C



_____ compressors require intake and discharge valves.

Select one:

A. Rotary

B. Centrifugal

C. Sliding vane

D. Rotary lobe

E. Reciprocating - (ANSWER)E



Besides reducing NOx, water injection systems

Select one:

a. stabilize the combustion process, thereby increasing the life of hot section components

b. help keep the compressor blading clean

c. reduce the gas turbine's thermal efficiency

d. decrease the power output - (ANSWER)C

, 3B2 Power Engineer Exam Practice Questions With Complete Solutions



The pressure at the outlet from the moving blades is the same as the pressure at the inlet to the moving
blades in a/an __________ turbine.

Select one:

A. Topping

B. Reaction

C. Back pressure

D. Impulse

E. Extraction - (ANSWER)D



A condenser shell may be fitted with an expansion joint if the:

Select one:

A. Expected temperature differentials will be greater than 20°C

B. Condenser tubes are U-shaped

C. Condenser is of welded construction

D. Condenser tubes are expanded into the tube sheets

E. Tube sheets are made of Admiralty brass - (ANSWER)D



Adjustable inlet diffuser vanes on centrifugal air compressors are implemented to:

Select one:

A. Change the operating characteristics of the compressor

B. Change the direction of the air flow to remove moisture

C. Remove foreign particles from the air

D. Only reduce the amount of air entering the compressor

E. Prevent back or reverse flow of air - (ANSWER)A



Positive displacement compressor types include:

1. Sliding vane

2. Axial flow