Induced voltage in an induction circuit is influenced by the rate of change of current and the characteristics of the inductor. In a parallel R-L circuit, if the inductor in one branch opens, the voltage across that branch is expected to remain constant due to the voltage generator. However, without specific details or a diagram, it is difficult to determine the exact behavior of the circuit. Assuming a perfect inductor, the resistance would be zero, leading to theoretically infinite current and induced voltage. More information is needed for a definitive answer.