Question

If the potential function is given by V = 4x + 3y, then the magnitude of electric field intensity at the point (2, 1) will be

• A. 11
• B. 5
• C. 7
• D. 1

Answer 1

Answer: (C)

7

Answer 2

As shown in figure Net electric field at A

$E = \sqrt { E _ { B } ^ { 2 } + E _ { C } ^ { 2 } + 2 E _ { B } E _ { C } \cos 60 }$ $E_{B} = E_{C} = \frac{1}{4\pi\varepsilon_{0}}.\frac{Q}{a^{2}}$

So, $E = \frac{\sqrt{3}Q}{4\pi\varepsilon_{0}a^{2}}$