Engineering Thermodynamics - Study Mode

[#176] A cycle consisting of two adiabatic and two constant pressure processes is known as
Correct Answer

(C) Joule cycle

[#177] A cycle consisting of one constant pressure, one constant volume and two isentropic processes is known as
Correct Answer

(D) Diesel cycle

[#178] A process, in which the temperature of the working substance remains constant during its expansion or compression, is called
Correct Answer

(B) Isothermal process

[#179] The ideal efficiency of a Brayton cycle without regeneration, with increase in pressure ratio will
Correct Answer

(A) Increase

Explanation

Solution: In a Brayton cycle without regeneration, the ideal efficiency increases with an increase in pressure ratio. The efficiency of a Brayton cycle without regeneration is given by: η = 1 - (1/r k-1 ) where η is the cycle efficiency, r is the pressure ratio (p max /p min ), and k is the specific heat ratio. As the pressure ratio increases, the denominator term (1/r k-1 ) decreases, resulting in a higher efficiency. Therefore, the correct option is Increase.

[#180] The ideal efficiency of a Brayton cycle with regeneration, with increase in pressure ratio will
Correct Answer

(B) Decrease