Two radioactive samples `1` and `2` have equal number of nuclei initially. They have halg-lives of `10` seconds and `20` seconds. The ratio of number of nuclei of `1` and `2` at `t=60` seconds is :

Two radioactive nuclei have same number of nuclei initially and decay constants as 5lambda . And 4lambda respectively. The ratio of number of nuclei will be 1/e^(2) after time:

Decay constants of two radio-active samples A and B are 15 x and 3x respectively . They have equal number of initial nuclei . The ratio of the number of nuclei left in A and B after a time (1)/(6x) is

Two radioactive materials X_1 and X_2 have decay constants 10 lamda and lamda respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of X_1 to that of X_2 will be 1//e after a time.

Two radioactive substances A and B have half lives of T and 2T respectively. Samples of a and b contain equal number of nuclei initially. After a time 4T , the ratio of the number of undecayed nuclei of A to the number if undecayed nuclei of A to the number of undeacyed nuclei of B is

Two radioactive materials A and B have decay constants 10lambda and lambda , respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of A of that of B will be 1//e after a time :

Two radioactive material A and B have disintegration constants 10lambda and2lambda respectively. If initially they have same number of nuclei, then the ration of number of nuclei of A and B will be (1)/(e) after a time of :

The radioactive materials X_1 and X_2 have decay constants 5lambda and lambda respectively. If intially they have the same number of nuclei, then the ratio of number of nuclei of X_1 to that of X_2 will be 1/e