Answer:
Explanation:
To determine the equivalent resistance of the assembly between points A and B, and to find out the percentage that the first 5 groups of resistances represent from the equivalent resistance, we would typically need to refer to "figure 3.129" which presumably shows the configuration of resistors. Since I don't have access to external images or specific figures, I can provide a general approach on how you might solve this problem:
1. **Calculate the Equivalent Resistance (R_AB)**:
- Look at the configuration of resistors in figure 3.129. Determine if the resistors are in series, parallel, or a combination of both.
- Apply the relevant formulas for series and parallel combinations to find the total resistance \( R_{AB} \) between points A and B.
2. **Determine the Resistance of the First 5 Groups**:
- Identify the resistors that belong to the first 5 groups in the configuration shown in figure 3.129.
- Calculate the total resistance \( R_{first\_5} \) for these resistors.
3. **Calculate the Percentage**:
- Once you have \( R_{AB} \) and \( R_{first\_5} \), calculate the percentage that the first 5 groups represent from the total equivalent resistance:
\[
\text{Percentage} = \left( \frac{R_{first\_5}}{R_{AB}} \right) \times 100\%
\]
Without the specific details of figure 3.129, I can't provide numerical values or specific calculations. However, this method outlines the steps you would take to find both the equivalent resistance and the percentage representation of the first 5 groups of resistances. If you can describe the configuration of resistors or provide more specific details from figure 3.129, I can offer more targeted assistance.