# V/I Ration for a conductor in Electric Current – Class 10 Science Experiment

## Activity Name: V/I Ration for a conductor in Electric Current

### Activity Description:

The aim of this experiment is to demonstrate that the ratio of potential difference (V) to current (I) is a constant for a conductor. The experiment involves connecting a circuit with a thin iron spoke and measuring the current and potential difference for different numbers of dry cells connected in series.

### Required Items:

• 5 dry cells of 1.5V each
• Conducting wires
• Ammeter
• Voltmeter
• Thin iron spoke of length 10cm
• LED
• Key

### Step by Step Procedure:

1. Connect the circuit as shown in Figure 10.
2. Solder the conducting wires to the ends of the iron spoke.
3. Close the key to allow current flow through the circuit.
4. Note down the readings of current (I) from the ammeter and potential difference (V) from the voltmeter in Table 1.
5. Connect two cells (in series) instead of one cell in the circuit.
6. Note down the respective readings of the ammeter and voltmeter and record them in Table 1.
7. Repeat the same process for three cells, four cells, and five cells, recording the values of potential difference (V) and current (I) for each case in Table 1.
8. Calculate the ratio V/I for each set of values.

### Experiment Observations:

• Upon analyzing the data in Table 1, it will be noticed that the ratio V/I remains constant for different numbers of cells connected in series.

Note down your observations in table format:

### Precautions:

1. Make sure to use conducting wires and connections with low resistance to avoid significant voltage drops.
2. Handle the circuit components and cells with care to prevent any damage or short-circuiting.
3. Double-check the connections before closing the key to avoid errors in readings.

### Lesson Learnt from Experiment:

The experiment demonstrates that the potential difference across a conductor (the iron spoke in this case) is directly proportional to the current passing through it, assuming the temperature of the conductor remains constant during the flow of current.