34 TREATISE ON ALTERNATING CURRENTS. 



Or, the root mean square current is numerically equal to the 

 maximum value divided by ^/2~ 

 If the E.M.F. is represented by 



e = E sin pt 

 the root mean square E.M.F. V, is similarly given by 



7 = 



We shall in future use the letters E.M.S. to indicate root mean 

 square values. 



It was proved, see 24, that in a reactive circuit of self- 

 induction L and capacity C 



VI- +(<*-*>)'( 



Therefore 



E 



or 



A = 



We see, therefore, that the equation 



E.M.F. 



Current = -: 



-: 

 impedance 



is true both for maximum and E.M.S. values of current and 

 E.M.F. 



PROBLEMS ON CHAPTER IV. 



1. What is the maximum current in a circuit having a capacity of 2 micro- 

 farads, and a resistance of 10 ohms, when an alternating E.M.F., whose maximum 



