Voltage Distribution Across Discs of Suspension Insulator Assembly

The voltage distribution across the discs of a suspension insulator assembly depends on several factors, including the geometry of the insulator, the line voltage, and the position of the insulator discs.

Factors Affecting Voltage Distribution:
1. Geometry of the Insulator: The suspension insulator assembly consists of several discs connected in series. Each disc has a specific diameter and thickness, which affects its capacitance and electric field distribution.

2. Line Voltage: The line voltage is the voltage carried by the transmission line. It is typically constant along the line unless there are variations due to losses or other factors. The line voltage determines the potential difference across each disc of the suspension insulator assembly.

3. Position of the Insulator Discs: The suspension insulator assembly is suspended between the transmission line and the tower. The position of the insulator discs determines their proximity to the line and the tower, which affects the voltage distribution.

Voltage Distribution Pattern:
The voltage distribution across the discs of the suspension insulator assembly is not the same for all discs. It is maximum for the unit nearest to the line and gradually decreases for the subsequent units towards the tower.

Explanation:
1. Electric Field Distribution: When a voltage is applied to the transmission line, an electric field is established around the line. The electric field lines are perpendicular to the line and spread out radially.

2. Capacitance Effect: Each disc of the suspension insulator assembly acts as a capacitor. The electric field lines intersect the surface of the discs, and a potential difference is established across each disc due to the capacitance effect.

3. Voltage Distribution: The potential difference across each disc depends on its proximity to the line and the tower. The disc nearest to the line experiences the highest potential difference because it is closer to the electric field lines. As we move towards the tower, the electric field lines spread out, resulting in a lower potential difference across the subsequent discs.

4. Maximum Voltage for Unit Nearest to the Line: Therefore, the voltage distribution across the discs of the suspension insulator assembly is maximum for the unit nearest to the line. This unit experiences the highest potential difference due to its proximity to the electric field lines.

5. Decreasing Voltage for Subsequent Units: The potential difference gradually decreases for the subsequent units towards the tower as the electric field lines spread out and the proximity to the electric field decreases.

Therefore, the correct answer is option 'B': Maximum voltage is experienced by the unit nearest to the line in the suspension insulator assembly.