Question

A point charge causes an electric flux of $-1.0\times 10^{3}N{m}^2/C$ to pass through a spherical Gaussian surface of $10.0cm$ radius centred on the charge. If the radius of the Gaussian surface was doubled, how much flux would pass through the surface?

• A. $-1.0\times 10^{3}N{m}^2/C$
• B. $-2.0\times 10^{3}N{m}^2/C$
• C. $-3.0\times 10^{3}N{m}^2/C$
• D. $-4.0\times 10^{3}N{m}^2/C$

Answer 1

Answer: (A)

Here, ${\varphi }_E=-1.0\times 10^{3}N{m}^2/C,r=10.0cm$
If the radius of Gaussian surface was doubled, flux passing through the surface would remain the same. This is because flux depends only on charge present inside the surface.