Power Cycles: Master the Fundamentals of Engineering Thermodynamics

Question 1

How does the Rankine cycle operate?

Accepted Answer

It uses a closed loop with water as the working fluid.

Accepted Answer

Its primary use is generating electricity in thermal power plants.

Answer

It's a purely theoretical concept with no practical applications.

Question 2

In Rankine cycles, which medium is primarily employed as the working fluid?

Accepted Answer

Water

Answer

Air

Answer

Ammonia

Answer

Carbon dioxide

Question 3

Which characteristic definitively identifies an Otto cycle?

Accepted Answer

Constant volume heat addition

Answer

Constant pressure heat addition

Answer

Adiabatic compression

Answer

Adiabatic expansion

Question 4

Isentropic efficiency measures the performance of a power cycle in relation to:

Accepted Answer

An ideal cycle

Answer

A practical cycle

Answer

A Carnot cycle

Answer

A Stirling cycle

Question 5

The specific work output of a power cycle is calculated as:

Accepted Answer

The difference between heat input and heat rejection

Answer

The ratio of heat input to heat rejection

Answer

The product of heat input and heat rejection

Answer

The square root of heat input minus heat rejection

Question 6

What is the main function of the compressor in a Brayton cycle?

Accepted Answer

Increase pressure and temperature of the working fluid

Answer

Decrease pressure and temperature of the working fluid

Answer

Transfer heat into the working fluid

Answer

Reject heat from the working fluid

Question 7

Which of the following is NOT a factor that influences the efficiency of a power cycle?

Accepted Answer

Turbine blade angle

Answer

Heat transfer rate

Answer

Pressure ratio

Answer

Ambient temperature

Question 8

For a Carnot cycle operating between two reservoirs at temperatures T1 and T2, what is the ideal efficiency?

Accepted Answer

1 - (T2 / T1)

Answer

(T1 - T2) / T1

Answer

(T1 + T2) / T2

Answer

T1 / (T1 - T2)

Question 9

What is the primary advantage of utilizing a regenerative heat exchanger in a power cycle?

Accepted Answer

Enhanced cycle efficiency

Answer

Reduced heat transfer requirements

Answer

Improved turbine performance

Answer

Reduced emissions

Question 10

What is the essential difference between a reversible and an irreversible process?

Accepted Answer

Reversible processes can be reversed without affecting entropy, unlike irreversible processes

Answer

Reversible processes occur at a constant temperature, unlike irreversible processes

Answer

Irreversible processes generate more heat than reversible processes

Answer

Reversible processes are more efficient than irreversible processes

Question 11

Which thermodynamic cycle is characterized by constant volume heat addition and isothermal expansion?

Accepted Answer

Otto Cycle

Answer

Rankine Cycle

Answer

Brayton Cycle

Answer

Diesel Cycle

Question 12

Which component of the Brayton cycle compresses the fluid?

Accepted Answer

Compressor

Answer

Turbine

Answer

Condenser

Answer

Evaporator

Question 13

What is the ideal thermal efficiency of the Carnot cycle?

Accepted Answer

1 - (T2 / T1)

Answer

T1 - T2 / T1

Answer

(T1 + T2) / T1

Answer

(T1 - T2) / (T1 + T2)

Question 14

Which of the following is a measure of the efficiency of a thermodynamic cycle?

Accepted Answer

Thermal efficiency

Answer

Mechanical efficiency

Answer

Electrical efficiency

Answer

Overall efficiency

Question 15

What is the purpose of a condenser in a thermodynamic cycle?

Accepted Answer

To condense the working fluid

Answer

To evaporate the working fluid

Answer

To compress the working fluid

Answer

To expand the working fluid

Question 16

Which of the following is NOT a power cycle type covered in this unit?

Accepted Answer

Stirling Cycle

Answer

Rankine Cycle

Answer

Otto Cycle

Answer

Brayton Cycle

Question 17

The efficiency of a power cycle is primarily determined by:

Accepted Answer

The ratio of net work output to total heat input

Answer

The pressure ratio of the cycle

Answer

The number of stages in the cycle

Answer

The type of working fluid used

Question 18

Which of the following applications is most commonly associated with the Rankine Cycle?

Accepted Answer

Steam power plants

Answer

Refrigeration systems

Answer

Gas turbine engines

Answer

Internal combustion engines

Question 19

The Brayton Cycle is typically employed in:

Accepted Answer

Gas turbine engines

Answer

Fuel cells

Answer

Reciprocating engines

Answer

Steam turbines

Question 20

The Otto Cycle is characteristic of:

Accepted Answer

Four-stroke gasoline engines

Answer

Diesel engines

Answer

Gas turbine engines

Answer

Steam turbines

Question 21

The compression ratio of a Diesel Cycle is typically:

Accepted Answer

Higher than in an Otto Cycle

Answer

Equal to the compression ratio of an Otto Cycle

Answer

Lower than in an Otto Cycle

Answer

Not applicable to Diesel Cycles