Practice portal › Electric Potential and Capacitance › Electric Potential

Electric potential at a point (x, y, z) m in a field is given by V = 5x² volt. Then the electric field at the point (1, 2, 3) m is ⃗E = ___ N C⁻¹.

Asked in GUJCET 2013 · Relation between field and potential

Answer: (4) -10 ̂i

Step-by-step solution

Given: V = 5x² (no y or z dependence); point (1, 2, 3) m.

Idea: ⃗E = -((∂ V)/(∂ x)̂i + (∂ V)/(∂ y)̂j + (∂ V)/(∂ z)̂k).

(∂ V)/(∂ x) = 10x, while (∂ V)/(∂ y) = (∂ V)/(∂ z) = 0.

At x = 1: ⃗E = -10x ̂i = -10 ̂i N C⁻¹.

The minus sign means the field points towards decreasing potential.

So ⃗E = -10 ̂i N C⁻¹.

Why the other options are wrong

More Electric Potential questionsAll Electric Potential questions →

Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.

Practise this with a timer