Maxwell Speed Distribution

Interpreting the distribution curve draws on the qualitative treatment of the Maxwell speed distribution in NCERT Class 11, Chapter 13 (Kinetic Theory). The distribution plots the fraction of molecules against their speeds, peaking at the most probable speed $v_p=\sqrt{\frac{2RT}{M}}$, which grows with temperature. Raising the temperature increases the most probable speed, so the peak shifts rightward to higher speeds; because the total area under the curve is fixed at one, the curve must flatten and broaden as it spreads over a wider range of speeds. The option that the peak moves to lower speeds contradicts the increase of $v_p$ with temperature. The option that the peak stays fixed ignores the temperature dependence of the most probable speed. The option describing a perfectly symmetric bell is wrong because the Maxwell curve is always skewed with a long high-speed tail. The requirement that the area under the curve stays equal to one reflects the simple fact that every molecule always has some definite speed, so the total fraction must remain unity. A plausibility check supports the answer: heating gives molecules more energy and a wider spread of speeds, so a lower, broader curve peaking at higher speed is the physically expected behaviour.