The activity of a sample of radioactive material is A1 at time t1 and A2 at time t2(t2 > t1). If its mean life is T, then The activity of a sample of radioactive material is A1 at time t1 and A2 at time t2(t2 > t1). If its mean life is T then November 28, 2020 Category: AIIMS Last 24 Years Solved 1996 - 2019 Physics and Chemistry Video Solutions , Chapter 31 - Nuclei , Physics , Facebook Messenger WhatsApp Share this:TwitterFacebook Related