Chapter Name: Electric Current
Activity Name: V/I Ration for a conductor in Electric Current
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.
- 5 dry cells of 1.5V each
- Conducting wires
- Thin iron spoke of length 10cm
Step by Step Procedure:
- Connect the circuit as shown in Figure 10.
- Solder the conducting wires to the ends of the iron spoke.
- Close the key to allow current flow through the circuit.
- Note down the readings of current (I) from the ammeter and potential difference (V) from the voltmeter in Table 1.
- Connect two cells (in series) instead of one cell in the circuit.
- Note down the respective readings of the ammeter and voltmeter and record them in Table 1.
- 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.
- Calculate the ratio V/I for each set of values.
- 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:
- Make sure to use conducting wires and connections with low resistance to avoid significant voltage drops.
- Handle the circuit components and cells with care to prevent any damage or short-circuiting.
- 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.