import math
#Variable declaration
Vp=15.#Vp=firing voltage of a unijunction transistor in Volts
VBB=40#VBB=source voltage in Volts
#Calculations&Results
n=(Vp/VBB)#n=intrinsic stand-off ratio
print "The intrinsic stand-off ratio is %.3f"%n
R=50*(10**3)#R=resistance in ohms
C=2000*(10**-12)#c=capacitance in farad
T=(R*C*math.log(1/(1-n)))*(10**6)#T=time period of the sawtooth voltage across C
print "The time period is %.f us"%T