Which of the following wiring diagrams could be used to experimentally determine `R` using ohm's law? Assume an ideal voltmeter and an ideal ammeter.

Options

A.
B.
C.
D.

Answer

To determine the resistance \( R \) using Ohm's law experimentally, we need to set up a circuit that allows us to measure both the current flowing through the resistor and the voltage across it. Here’s a step-by-step solution:

### Step 1: Understand Ohm's Law
Ohm's law states that \( V = I \cdot R \), where:
- \( V \) is the voltage across the resistor,
- \( I \) is the current flowing through the resistor,
- \( R \) is the resistance.

To determine \( R \), we need to measure \( V \) and \( I \).

### Step 2: Set Up the Circuit
1. **Connect the Resistor**: Place the resistor \( R \) in the circuit.
2. **Connect the Ammeter**: Connect an ideal ammeter in series with the resistor. This allows us to measure the current \( I \) flowing through the resistor.
3. **Connect the Voltmeter**: Connect an ideal voltmeter in parallel with the resistor. This allows us to measure the voltage \( V \) across the resistor.

### Step 3: Measure Voltage and Current
- Turn on the power supply and adjust it to a known value.
- Record the current \( I \) displayed on the ammeter.
- Record the voltage \( V \) displayed on the voltmeter.

### Step 4: Calculate Resistance
Using the values obtained from the measurements:
\[ R = \frac{V}{I} \]
This formula gives us the resistance \( R \) of the resistor based on the measured voltage and current.

### Step 5: Repeat Measurements
To ensure accuracy, repeat the measurements for different voltage settings and calculate \( R \) each time. The average value can provide a more reliable result.

### Conclusion
The wiring diagram that connects the voltmeter in parallel and the ammeter in series with the resistor is the correct setup to experimentally determine \( R \) using Ohm's law.

---