that is 



INDUCTIVE CIRCUITS. 

 / = 



(2) 



and if the instantaneous value of the P.D. is given by e sin pt, 

 the instantaneous value of the current is given by 



. _ e sin (pt 0) 



Equation (2), it must be noticed, is not the same as equa- 

 tion (1) ; it is one of several deductions from equation (1), and 



while (1) is a vector equation involving directions as well as mag- 

 nitudes, (2) involves magnitudes only. 



Equation (2) gives us the maximum or the "R.M.S. value of the 

 current when the maximum or the E.M.S. value of the P.D. is given. 

 It also tells us that the impedance (see 21) of the circuit is 



Referring again to equation (1), it may be written 

 I(r -f TcpL) = e 



or 



r 4- 



(r kpL)e 



~ (r~+ kpL)(r - kpL) 

 (r- 



