Question

The electric potential V is given as a function of distance x (meter) by V = (5x² + 10x – 9) volt. Value of electric field at x = 1 is ……. 

(A) – 20(v/m) 

(B) 6(v/m) 

(C) 11(v/m) 

(D) – 23(v/m)

Answer 1

The correct option (A) – 20(v/m)

Explanation:

v = 5x² + 10x – 9

as E = [(– dv)/dx] = [(– d)/dx] (5x² + 10x – 9)

E = – 10x – 10

∴ E = at x = 1 is (– 10) (1) – 10 = – 20(v/m)