ELECTRIC MOMENTUM. INDUCTANCE. 



149 



cause the current to increase at a rate of 10 amperes per second 

 in accordance with equation (49).* 



The ordinates of the curve in Fig. 96 represent the successive 



Growing current 

 R=3 ohms 

 L=0.04 henry 

 E~110 volts 



hundredth* of a second 



23456 78 



Fig. 96. 



values of growing current in a circuit of which the resistance is 3 

 ohms and the inductance is 0.04 henry, the electromotive force 

 of the generator being 1 1 o volts. The equation to this curve of 



growing current is 



F. F. _:? * 



(52) 



E 

 R 



in which e is the Naperian base, i is the value of the growing 

 current t seconds after the electro- 

 motive force E is connected to the 

 circuit, L is the inductance of the 

 circuit and R is its resistance. 



f V 



79. Decay of current in an induc- 

 tive circuit. A current / is es- 

 tablished in an inductive circuit, a 

 piece of metal mm is then laid 

 across the terminals of the circuit 

 and the battery disconnected as in- 

 dicated by the dotted line in Fig. 97. 



i T 

 t_J " 



Fig. 97. 



Under these conditions 



* Ohm's law does not apply to a circuit unless El equals RP as stated in Art. 19. 



