At time `t=0`, some radioactive gas is injected into a sealed vessel. At time `T`, some more of the same gas is injected into the same vessel. Which one of the following graphs best represents the variation of the logarithm of the activity `A` of the gas with time `t`?

Options

A.
B.
C.
D.

Answer

B

Explanation

`A - A_(01) e^(-lamda t)`
`l n A - l n A_(0) - lamda t`
`l n` A versus t is a linearly decreasing graph with slope depending to `lamda` As `lamda` does not change, slope is charge remains same.