First Law Of Thermodynamics MCQ - Practice Questions with Answers

The first law of thermodynamics - 

According to it, heat given to a system (Q) is equal to the sum of the increase in its internal energy (U) and the work done (W) by the system against the surroundings.

$$\mathrm{\Delta }Q=\mathrm{\Delta }U+\mathrm{\Delta }W$$

or For cyclic process

$$\sum \mathrm{\Delta }Q=\sum \mathrm{\Delta }W$$
Drawback of the First law of thermodynamics -

• The first law of thermodynamics does not tell us the reason for the direction of heat transfer.

Important points - 

1. Q and W are the path functions but U is the point function.

2. The first law of thermodynamics introduces the concept of internal energy.