How can i apply the Kirchoffs law?
Answers
(i) Starting from the positive terminal of the battery having highest emf, distribute current at various
junctions in the circuit in accordance with ‘junction rule’. It is not always easy to correctly guess the
direction of current, no problem if one assumes the wrong direction.
(ii) After assuming current in each branch, we pick a point and begin to walk (mentally) around a
closed loop. As we traverse each resistor, capacitor, inductor or battery we must write down, the voltage
change for that element according to the above sign convention.
(iii) By applying KVL we get one equation but in order to solve the circuit we require as many equations
as there are unknowns. So we select the required number of loops and apply Kirchhoff’s voltage law across
each such loop.
(iv) After solving the set of simultaneous equations, we obtain the numerical values of the assumed
currents. If any of these values come out to be negative, it indicates that particular current is in the opposite
direction from the assumed one.