Question

What is the difference between first and second laws of thermodynamics?

Answer 1

The First Law of the Thermodynamics is related to the conservation of energy, while the Second Law of Thermodynamicsargue that some of the thermodynamics processes are impermissible and does not entirely follow the First Law of Thermodynamics.
The word ‘thermodynamics‘ is derived from the Greek words, where “Thermo” means heat and “dynamics” means power. So thermodynamics is the study of energy which exists in various forms like light, heat, electrical and chemical energy.

Thermodynamics is very vital part of the physics and its related field like chemistry, material science, environmental science, etc. Meanwhile ‘Law’ means the system of the rules. Therefore laws of thermodynamics deal with the one of the forms of energy which is heat, their behaviour under different circumstances corresponding to the mechanical work.

Though we know that there are four laws of thermodynamics, starting from the zeroth law, first law, second law and the third law. But the most used are the first and the second laws, hence in this content, we will be discussing and differentiating the first and second laws.

Answer 2

BASIS FOR COMPARISON FIRST LAW OF THERMODYNAMICS SECOND LAW OF THERMODYNAMICS

Statement

Energy can neither be created nor be destroyed.

The entropy (degree of disorders) of an isolated system never decreases instead always increases.

Expression

ΔE = Q + W, is used for the calculation of the value if any two quantity is known. ΔS = ΔS(system) + ΔS(surrounding) > 0

Expression implies that The change in the internal energy of a system is equal to the sum of the heat flow into the system and work done on the system by the surrounding. The total change in the entropy is the sum of the change in the entropy of the system and surrounding which will increase for any real process and cannot be less than 0.

Example

1. Electric bulbs, when lighten converts electric energy into the light energy (radiant energy) and heat energy (thermal energy).

2. Plants convert the sunlight (light or radiant energy) into chemical energy in the process of photosynthesis. 1. The machines convert the highly useful energy like fuels into the less useful energy, which is not equal to the energy taken up while starting the process.

2. The heater in the room uses the electric energy and give out heat to the room, but the room in return can't provide the same energy to the heater