29. a nucleus has two states with energies 1 mev and 2 mev. if the life time of lower state is 2 ns, then the life time in higher state will be (a) 10 ns (b) 20

29. A nucleus has two states with energies 1 MeV and 2 MeV. If the life time of lower state is 2 ns, then the life time in higher state will be (A) 10 ns (B) 20 ns (C) 0.5 ns (D) 1 ns