FIRST LAW OF THERMODYNAMICS

FIRST LAW OF THERMODYNAMICS

First Law: - If a closed system is undergone in a cyclic process, then mechanical work done is directly proportional to the Heat Transfer.

• Heat and work mutually convertible in a cyclic process.
• Applicable for reversible as well as irreversible process.
• For isolated system energy(E) always constant.
• for an ideal gas, Internal energy depends on temperature only.
• Follow Conservation of Energy rules.
• Total energy of a system E = E_p + E_k + U

• Enthalpy depends only on temperature.
• First law of thermodynamics furnishes the relationship between Heat, work and properties of the system.
• First law of thermodynamics was developed by Joule.
• First law doesn't help to predict whether the system will or not undergo a change.
• Does not  enable to determine change in entropy.

PMM 1 (Perpetual Motion Machine First Kind): -

There can be no machine which would continuously supply mechanical work without some other form of energy disappearing simultaneously. 

Such a fictitious machine is called Perpetual Motion Machine of the first kind.

• A machine that continuously creates its own energy.