Engineering :: Thermodynamics

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191.

In all irreversible processes, the entropy of the system

A.	Increases	B.	Reduces to zero
C.	Remains constant	D.	Sometimes increases and sometimes decreases
E.	Depends on medium

192.

In a Carnot engine, when the working substance gives heat to the sink

A.	The temperature of the sink increases	B.	The temperature of the sink remains the same
C.	The temperature of the source decreases	D.	The temperature of both the sink and the source decreases
E.	Changes depend on the operating conditions

193.

If the temperature of the source is increased, the efficiency of the Carnot engine

A.	Decreases	B.	Increases
C.	Does not change	D.	Will be equal to the efficiency of a practical engine
E.	Depends on their factors

194.

The efficiency of an ideal (Carnot engine) depends on

A.	Working substance	B.	On the temperature of the source only
C.	On the temperature of the sink only	D.	On the temperature of both the source and the sink
E.	On the construction of engine

195.

If molar Cp = 4.97 then

A.	Cv = 2.97	B.	Cv = 1.97
C.	Cv = 5.97	D.	Cv = 0.97
E.	Cv = 0.597

196.

In an isothermal process change in internal energy

A.	Decreases	B.	Increases
C.	Remains constant	D.	Becomes zero
E.	Depends on the friction and other factors

197.

In an isothermal expansion of gases

A.	Temperature is lowered	B.	Temperature is raised
C.	Temperature is unaltered	D.	Temperature becomes zero
E.	Temperature shows the extent of expansion

198.

The triple point of a substance is the temperature and pressure at which

A.	The solid and liquid phases are in equilibrium	B.	The liquid and gaseous phases are in equilibrium
C.	The solid, liquid and the gaseous phases are in equilibrium	D.	The solid does not melt, the liquid does not boil and the gas does not condense

199.

A heat engine works on a Carnot cycle with a heat sink at a temperature of 27?C. The efficiency of the engine is 10%, the temperature of the heat source is

A.	30?C	B.	270?C
C.	60?C	D.	10?C

200.

Food can be cooked quicker in a pressure cooker because

A.	Less heat is lost	B.	High pressure steam has high temperature
C.	Steam remains within the cooker	D.	It is made of a metal
E.	None of the above