In [1]:

```
import math
#Variables
I = 40 #Current (in milli-Ampere)
t = 15 * 10**-3 #time (in seconds)
CFS = 93 #Circuit fusing rate (in Ampere-square second)
#Calculation
SCR = I**2 * t #Surge in the device (in Ampere-square second)
#Result
print "Since value of SCR i.e. ",SCR," A**2s is less than CFS i.e. ",CFS," A**2s."
print "Therefore the device will not be destroyed."
```

In [2]:

```
import math
#Variables
SCR = I2t = 75.0 #SCR (in Ampere-square second)
IS = 100.0 #Current (in Ampere)
#Calculation
tmax = I2t / IS**2 #Maximum allowable time (in seconds)
#Result
print "Maximum allowable time is ",tmax * 10**3," ms."
```

In [3]:

```
import math
#Variables
VD = 0.7 #Voltage (in volts)
n = 0.75 #Intrinsic stand-off ratio
VBB = 12 #Base Voltage (in volts)
#Calculation
VP = n * VBB + VD #Peak-point voltage (in volts)
#Result
print "Peak - point voltage of the circuit is ",VP," V."
```

In [4]:

```
import math
#Variables
rB1 = 4.0 #Resistance (in kilo-ohm)
rB2 = 2.5 #Resistance (in kilo-ohm)
VBB = 15.0 #Base voltage (in volts)
VD = 0.7 #Voltage (in volts)
#Calculation
n = rB1 / (rB1 + rB2) #Intrinsic stand-off ratio
VP = n * VBB + VD #Peak-point voltage (in volts)
#Result
print "Intrinsic stand off ratio is ",round(n,4),".\nPeak-point voltage is ",round(VP), "V."
```

In [5]:

```
import math
#Variables
n = 0.60 #Intrinsic stand-off ratio
rBB = 7.0 #Base- Bulk resistance (in kilo-ohm)
#Calculation
rB1 = n * rBB #Resistance (in ohm)
rB2 = rBB - rB1 #Resistance (in ohm)
#Result
print "Static values of rB1 is ",rB1," kilo-ohm and of rB2 is ",rB2," kilo-ohm."
```