DRAWING GRAPHS OF TRANSIENTS

THE TREATMENT described here is intended only for elementary students. For many, the method described in Dr Hughes' ‘Principles of Electricity in M.K.S. Units’ (page 140) may be more suitable; but it involves the use of algebra to show that the time constant of a circuit containing inductance and resistance is given by L/R; and no reference is made to the graph of induced e.m.f., nor to the graph for the decay of the current (only the growth of current is discussed). For an elementary class which had seen the waveforms described last month, a treatment was required which would be arithmetical rather than algebraic, and would be adapted to the circuit of. Figure. 1, which differs slightly from that to which Dr Hughes' treatment applies.