Q.Find the equivalent resistance between the terminals F and B in the network shown in the figure below, given that the resistance of each resistor is 10 ohm. [content not recoverable from extraction -- the circuit diagram showing how the resistors are wired between F, B and the other labelled nodes did not survive the PDF text extraction, so the topology needed to independently verify or derive the printed answer is unavailable.]

Kirchhoff's Laws and Circuit Analysis

Complex circuits that cannot be reduced to simple series–parallel combinations are solved with Kirchhoff's two rules:

• Junction (current) rule — the algebraic sum of currents meeting at a node is zero, $\sum I = 0$. It expresses conservation of charge.
• Loop (voltage) rule — around any closed loop the algebraic sum of EMFs and $IR$ drops is zero, $\sum \varepsilon = \sum IR$. It expresses conservation of energy.

To apply them, assign a current to each branch, write one junction equation per independent node and one loop equation per independent mesh, and solve the simultaneous equations; a negative answer simply means the assumed direction was reversed. Where node potentials are given, the current in a branch follows directly from Ohm's law, $I=(V_1-V_2)/R$, and the junction rule fixes an unknown branch current from the others. …