radioactive isotopes are produced in a nuclear physics experiments at constant rate dN/dt = R. An inductor of inductance mH a resistor of resistance Ω and a battery are connected to form a series circuit . the circuit is switched on at the instant the production of radioactive isotope starts it is found that i?N remains constant in time where i us the current in the circuit at time t and N is the number of active nuclei at time t. find the half-life the isotope