Question

A point charge of 10 X 10^-6 C is at the centre of a cubical Gaussian surface of sides 0.5 m. What is the flux for the surface?

(a) 1.12 X 10^5 Nm^2/C

(b) 2.45 X 10^5 Nm^2/C

(c) 3.12 X 10^5 Nm^2/C

(d) 3.45 X 10^5 Nm^2/C

Answer 1

Right answer is (a) 1.12 X 10^5 Nm^2/C

Explanation: We know that for a Gaussian surface, flux = q/ε

Here, q = 10^-6 C and ε = 8.85 X 10^-12 C/Nm^2

Therefore, flux = 10^-6/8.85 X 10^-12

= 1.12 X 10^5 Nm^2/C.