JEE Main20266 April 2026Evening ShiftPhysicsElectrostaticsActual
The electric potential as a function of x, y is given by V = 5(x^2 - y^2) V. The electric field at a point (2, 3) m is __________ V/m.
Options
- A(-20 i + 30 j )
- B(20 i - 30 j )
- C(20 i + 45 j )
- D(-4 i + 6 j )
Correct answer
A. (-20 i + 30 j )
Step-by-step solution
The electric field E is given by the negative gradient of the electric potential V : E = - ( V x i + V y j ) Given V = 5(x^2 - y^2) , we find the partial derivatives: V x = 10x V y = -10y Substituting these into the expression for E : E = -(10x i - 10y j ) = -10x i + 10y j At the point (2, 3) , substitute x = 2 and y = 3 : E = -10(2) i + 10(3) j = -20 i + 30 j V/m Answer: (-20 i + 30 j )