A gas mixture consists of 2 moles of O2 and 4 moles of Ar at temperature T. Neglecting all vibrational modes, the total internal energy of the system is:
Radioactive material 'A ' has decay constant '8λ ' and material 'B ' has decay constant 'λ '. Initially they have same number of nuclei. After what time, the ratio of number of nuclei of material 'B ' to that of 'A ' will be e1?