Question

A point charge causes an electric flux of $-1.0x\times 10^{3}N{m}^2{C}^{-1}$ to pass through a spherical Gaussian surface of 10.0 cm radius centred on the charge. If the radius of the Gaussian surface were three times, how much flux would pass through the surface?

• A. $30\times 10^{3}N{m}^2{C}^{-1}$
• B. $-10\times 10^{3}N{m}^2{C}^{-1}$
• C. $-3.0\times 10^{3}N{m}^2{C}^{-1}$
• D. $-2.0\times 10^{3}N{m}^2{C}^{-1}$

Answer 1

Answer: (B)

According to Gauss's theorem electric flux ($\varphi$) through a closed surface S is $\frac{q}{{\epsilon }_0}$
Electric flux ( $\varphi$ )passes through the sphericaI Gaussian surface is independent of the radius of the paussian surface but depends only on the charge enclosed by the surface. On increasing the radius of Gaussian surface three times. there wouid be no effect on electric flux.