Internal Resistance Lab

Part A: Circuit Simulation

Instructions: Investigate the relationship between current (I) and terminal potential difference (V). The dashed box represents a real battery with internal resistance (r).

External Resistance (R-ext): 5.0 Ω

Terminal Potential Difference (V)

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Volts (V)

Circuit Current (I)

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Amperes (A)

Part B: Results Table

Trial	External Resistance (Ω)	Current I (A)	Terminal P.D. V (V)

Part C: Graph Analysis

Plot Terminal Voltage (V) vs Current (I).

Part D: Calculations

Student Name:

Grade:

1. Determine the Gradient

Select two points from your graph to calculate the gradient (slope):

Point 1 - Current (I1) in A:

Point 1 - Voltage (V1) in V:

Point 2 - Current (I2) in A:

Point 2 - Voltage (V2) in V:

2. Apply the EMF Formula

The relationship between terminal voltage, EMF, current, and internal resistance is: V = ε - Ir

Y-intercept (EMF, ε) in V: