Chapter 4: Chemical effects of electricity

Example 1, page no. 35

from __future__ import division
#initializing the variables:
R = 0.2; # in ohms
n = 8; # no. of cells
e = 2.2; # in volts

#calculation:
es = n*e
ep = e
Rs = n*R
Rp = R/n

#results
print "(a)Resistance", Rs,"ohms; e.m.f", es,"Volts(V)"
print "(b)Resistance", Rp,"ohms; e.m.f", ep,"Volts(V)"

(a)Resistance 1.6 ohms; e.m.f 17.6 Volts(V)
(b)Resistance 0.025 ohms; e.m.f 2.2 Volts(V)

Example 2, page no. 35

from __future__ import division
#initializing the variables:
r = 0.02; # in ohms
e = 2; # in volts
I1 = 5; # in Amperes
I2 = 50; # in Amperes

#calculation:
pd1 = e - (I1*r)
pd2 = e - (I2*r)

#results
print "(a)p.d", pd1,"Volts(V)"
print "(b)p.d", pd2,"Volts(V)"

(a)p.d 1.9 Volts(V)
(b)p.d 1.0 Volts(V)

Example 3, page no. 36

from __future__ import division
#initializing the variables:
e1 = 25; # in volts
e2 = 24; # in volts
I2 = 10; # in Amperes

#calculation:
r = (e1 - e2)/I2

#results
print "Resistance", r,"Ohms"

Resistance 0.1 Ohms

Example 4, page no. 36

from __future__ import division
#initializing the variables:
r = 0.2; # in ohms
n = 10; # no. of cells
e = 1.5; # in volts
R = 58; # in ohms

#calculation:
es = n*e
rs = n*r
I = es/(rs + R)
pd = es - (I*rs)

#results
print "(a)Current", I,"Amperes(A)"
print "(b)p.d", pd,"Volts(V)"

(a)Current 0.25 Amperes(A)
(b)p.d 14.5 Volts(V)