exer4_10.m

%EXER4_10       Solves exercise 4.10, A bridge that cannot be balanced.

% a)
f = 400;                          % frequency, Hz
Z1 = 10000 - j/(2*pi*f*1*10^(-6)) % ohm
Z2 = 5000 + j*0.001*2*pi*f        % ohm
R4 = 10000;                       % ohm
R3 = Z1*R4/Z2

% b)

 f = 50;                           % frequency, Hz
 Z1 = 30000 - j/(2*pi*f*2*10^(-6)) % ohm
 Z2 = 10000 + j*0.002*2*pi*f       % ohm
 R4 = 30000;                       % ohm
 R3 = Z1*R4/Z2

disp('In both cases the calculated value of $ R_3 $ has a negative')
disp('imaginary part. The bridge cannot be balanced if R3 is a pure')
disp('resistance; there should be also a capacity.')