Question

Given an external electric field with potential V(r) = A/r where A = 9 × 10⁵ N C⁻¹ m², what is the external potential at distance r = 0.09 m?

Options

• \[V(r) = 10^5\text{ V}\]

• \[V(r) = 10^8\text{ V}\]

• \[V(r) = 10^7\text{ V}\]

• \[V(r) = 10^6\text{ V}\]

Answer 1

The external potential is calculated as \[V(r) = \frac{A}{r} = \frac{9\times10^5}{0.09} = 10^7\text{ V}\]. This straightforward division applies the given potential function directly to find the value at the specified distance.