Problem 3
A source with constant emf and internal resistance is connected to a resistive load . Neglect lead resistance; let be current, the terminal and load voltage, and the load power. (a) Find current. (b) Find load voltage. (c) Find load power and power lost inside the source. Keep the sign convention consistent and use appropriate SI units throughout. Each part builds on intermediate results from the preceding part; apply a physical relation only where the stated model assumptions hold. Finally compare the answers with the initial conditions, expected trends, and an independent check when available.
problems.proof.stepOf
problems.proof.analysis
Apply the governing law for the stated model, using the sign convention in the problem. This provides the starting equation for the later parts.
problems.proof.pitfall. Do not equate emf E with load voltage U; internal resistance causes a drop Ir.