When the temperature of a gas is raised from 270C to 900C, the percentage increase in the rms velocity of the molecules will be
10 %
15 %
20 %
17.5 %
C'C = 273+90273+27 = 363300
or C'C = 1.21 = 1.1
or C'C -1 = 0.1
or C'-CC×100 = 0.1 × 100 = 10%