Thermodynamics

Which law of thermodynamics is used to understand the concept of energy conservation?

• Zeroth law

• First law

• Second law

• None of these

In which thermodynamic process is there no flow of heat between the system and the surroundings.

• Isobaric

• Isothermic

• Adiabatic

• Isochoric

If the temperature of the source is increased, the efficiency of carnot heat engine

• Increases

• Decreases

• Remains constant

• First increases then becomes constant

An ideal heat engine operates in Carnot's cycle between 227 degree C and 127 C. it absorbs 6 x 10 ^4 J at high temperature. The amount of heat converted into work is

• 4.8 x 10^4 J

• 3.5 x 10^4 J

• 1.6 x 10^4 J

• 1.2 x 10^4 J

What is the source temperature of the Carnot engine in K required to get 70% efficiency? Given sink temperature is 27 degree C.

• 1000 K

• 90 K

• 270 K

• 727 K

110 Joule of heat is added to a gaseous system, whose internal energy is 40 J.

Then the amount of external work done is

• 150 J

• 70 J

• 110 J

• 40 J

The efficiency of carnot heat engine

• 1+(Temperature of sink/Temperature of source)

• 1-(Temperature of sink/Temperature of source)

• 1+(Temperature of source/Temperature of sink)

• 1+(Temperature of source/Temperature of sink)

The second law of thermodynamics introduces the concept of

• Heat

• Temperature

• Entropy

• Internal energy of the system

In thermodynamics, which is not a state variable

• Density

• Internal Energy

• Enthalpy

• Heat

Heat does not spontaneously flow from a colder body to a hotter one. Which of the following thermodynamics law states this?

• Zeroth law of thermodynamics

• First law of thermodynamics

• Second law of thermodynamics

• Third law of thermodynamics