AIM: To verify Ohm's law in a series-parallel circuit. (a)-(m) are instructions for the experiment and data analysis.

The voltmeter $V_x$ measures the voltage across resistor $R_1$, and the ammeter measures the current $I$ flowing through $R_1$. According to Ohm's law, the voltage across a resistor is directly proportional to the current flowing through it, with the resistance being the constant of proportionality.

When $V_x$ is plotted on the vertical axis (y-axis) and $I$ on the horizontal axis (x-axis), the equation $V_x = I \cdot R_1$ is in the form $y = mx$, where $m$ is the slope.
Therefore, the slope $K$ of the $V_x$ versus $I$ graph represents the resistance of resistor $R_1$.

The slope $K$ represents the resistance of $R_1$.

m) How does the result in 2(l) satisfy Ohm's law?

Part (l) asks to evaluate the product of the slope $K$ and the current $I$ at a specific voltage $V_x = 3 \, \text{V}$. From part (k), we know that the slope $K$ represents the resistance $R_1$. So, the product $K \cdot I$ is equivalent to $R_1 \cdot I$.

Ohm's law states that the voltage across a resistor is equal to the product of the current flowing through it and its resistance ($V = IR$). In this experiment, $V_x$ is the voltage across $R_1$, and $I$ is the current through $R_1$. Thus, Ohm's law for $R_1$ is $V_x = I \cdot R_1$.

If the experiment is performed correctly, the product $K \cdot I$ (which is $R_1 \cdot I$) calculated in part (l) should be equal to the corresponding voltage $V_x$ (which is $3 \, \text{V}$). This equality, $V_x = K \cdot I$, directly demonstrates and verifies Ohm's law for resistor $R_1$.