Question

In (Figure 1), two objects, O1 and O2, have charges +4.0μC and −4.0μC, respectively, and a third object, O3, is electrically neutral.

Part A

What is the electric flux through the surface A1 that encloses all three objects?

Part B

What is the electric flux through the surface A2 that encloses the third object only?

Answer 1

Electric flux through a closed gaussian surface is given by:

Q_net = net charge inside surface A1 = O1 + O2 + O3 = +4.0 C - 4.0 C + 0 C = 0 C

= Vacuum permittivity = 8.854*10^-12

So,

= 0*10^-6/(8.854*10^-12) = 0 N.m^2/C

In two significant figures

= 0.0 N.m^2/C

B.

Q_net = net charge inside surface A2 = O3 = 0 C

So,

= 0/(8.854*10^-12) = 0 N.m^2/C

In two significant figures

= 0.0 N.m^2/C

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