A DC source of EMF E is connected to a series LR circuit. At the instant when the current equals half its final value, what is the magnitude of the voltage across the inductor?
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A DC source of EMF E is connected to a series LR circuit. At the instant when the current equals half its final value, what is the magnitude of the voltage across the inductor?

G1 Physics · Accepted Answer

Kirchhoff's law gives E=IR+VL. At I=E/(2R), IR=E/2, hence VL=E/2.