Question

Electric potential at any point is V = – 5x + 3y + √(15z), then the magnitude of the electric field is……..N/C. 

(A) 3√2 

(B) 4√2 

(C) 7 

(D) 5√2

Answer 1

The correct option (C) 7

Explanation:

V = – 5x + 3y + √(15)z

as E_x = [(– dV)/dx] = [(– d)/dx] [– 5x + 3y + √(15)z] = 5

Ey = [(– dV)/dy] = [(– d)/dy] [– 5x + 3y + √(15)z] = − 3

Ez = [(– dV)/dz] = [(– d)/dz] [– 5x + 3y + √(15)z] = – √(15)

∴ E = √(Ex² + Ey² + Ez²)

= √[(5² + (– 3)² + {– √(15)}²]

= √(25 + 9 + 15)

E = 7 N/C