The following graph represents the T-V curves of an ideal gas ( where T is the temperature and V the volume) at three pressures P1, P2 and P3 compared with those of Charles's law represented as dotted lines.
Then the correct relation is :
Step 1: State Charles's Law
Charles's law dictates that at a constant pressure, the volume of an ideal gas is directly proportional to its absolute temperature:
$$ V \propto T \quad \text{(at constant P)} $$
Step 2: Interpret the Graph
The slope of each curve in the Temperature-Volume (T-V) graph is defined as:
$$ \text{Slope} = \frac{1}{P} $$
For a specific curve, pressure (P) is held constant. Therefore, a steeper slope signifies a lower pressure.
Step 3: Evaluate Slopes
\( P_1 \) exhibits the smallest slope, implying the highest pressure.
\( P_3 \) exhibits the steepest slope, implying the lowest pressure.
Step 4: Final Determination
The pressures are ordered as follows:
$$ P_1 > P_2 > P_3 $$