what will be the resistance between a and b
Answers
We will try to solve the above circuit by concept of WS(Wheat-Stone) bridge.
It can be clearly seen that circuit AEGHFD is a Wheat-Stone Bridge. Thus no current flows through the branch EF. Hence the resistor EF can be considered detached. And similarly EGBCHF is a Wheat-Stone Bridge. Thus, no current flows through the branch GH and hence it can also be considered as detached.
Thus, Equivalent resistance of the branch AB is:
R(ag) = 10 + 10 + 10 = 30ohm ................(i)
Hence, the answer to your question is 30ohm.
So, here your question ends. But for the sake of physics, let's try to find out equivalent resistance of the whole circuit. And here it goes:
Equivalent resistance of the branch DC is:
R(dh) = 10 + 10 + 10 = 30ohm ................(ii)
Hence, equivalent resistance between the branches AB and DC is:
R(eq) = (30)/2 = 15ohm ...............(iii)
Thus, the equation (iii) gives us the resistance of the whole circuit.
=> Resistance of the whole circuit is 15ohm.
and, equation (i) gives us the resistance between points (a) and (b)
=> Resistance between points (a) and (b) is 30ohm.
:)
