Question

Along with limiting corona and its effects, particularly for EHV lines, the maximum ground-level electric field strength needs to be controlled to avoid the shock hazard.

(a) True

(b) False

Short answer

Therefore, the correct option is (a) True.

Step-by-step solution

Determine the formula of electric field strength.

Write the formula of electric field strength on the conductor by neglecting the electric field due to the charges on other conductor.

${\mathbf{E}}_{\mathbf{r}}\mathbf{=}\frac{\mathbf{q}}{\mathbf{2}\mathbf{\pi \epsilon r}}$ ……. (1)

Here, $\mathrm{r}$ is the radius of conductor.

Determine the correct option

The rough value of breakdown voltage is$30\frac{\mathrm{kV}}{\mathrm{cm}}$.

To control the corona effect, the transmission lines are designed in a way that the electric field strength on conductor surface is below $20\frac{\mathrm{kV}}{\mathrm{cm}}$.

For low voltage transmission line, the corona can be controlled, but for extra high voltage (EHV) lines, the concern for corona is more.

The possibility of corona and shock hazard are of more concern in EHV lines.

Hence,for EHV lines, the maximum ground-level electric field strength needs to be controlled to avoid the shock hazard.

Therefore, the correct option is (a) True.