through a Coil of Variable Inductance. 



159 



with three different values of the resistance, and these agree 

 to within 1 per cent, with calculation. 



Exactly the same method of procedure is adopted when 

 plotting the discharge through a coil of variable inductance, 

 the straight line KM being replaced by a curve drawn to 



Fu>\ 2. — Curve showing- the Discharge of a Condenser of 1*25 m.f. 

 . Capacity through a Coil having a Core of Soft Iron Wire. 

 P.D. before Discharge = 9400 volts. 

 Time for Half-Oscillation =2-9 X 10~ 5 sees. 

 Experimental value = 3'2 X 10-5 sees. 









TC-20«* 



rtiOO 





















2 



















|.A 













\ 



30 20 10 



-b' IN I0" 5 S£CS 



15 20 25 



Time in I0""sec£ 



Fig. 3. — Curve showing the Discharge of a Condenser of 1*25 m.f. 

 Capacity through a Coil having a Core of Soft Iron Wire. 

 P.D. before Discharge = 2350 volts. 

 Time for Half-Oscillation = 51 X 10-5 sees. 



r 20 15 10 



20 25 30 

 Time, in IO~*SecS 



Fig. 4. — Curve showing the Discharge of a Condenser of 1*25 m.f. 

 Capacity through a Coil having a Core of Soft Iron Wire. 

 P.D. before Discharge = 450 volts. 

 Time for Half-Oscillation = 15-2 X 10-5 seC s. 









c 



hm- 



& — 











A 



























/ \ 

















1 



























J 

























A i 



















240 160 



-R-//V \q- 5 $ecs 



60 80 100 



Time in 10"* SECS 



L' 



represent the variation in the value of ]T - with current. 

 Such curves are shown at A A in figs. 2, 3, and 4. 



