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Hi everyone, I am struggling with gauss law. I understand the basic concept , but I can not relate it to other physics problems. I have this physics problem. I want to really understand physics, but I can't. I have watched a lo of videos but I still don't understand. I am going to give my approach to this problem and you guys tell me what is the problem in my understanding in physics
I understand that in a electrostatic condition, the net field inside the conductor must be zero otherwise particles would be moving. If we consider a circle with a cavity without charge, i would expect that the surface doesn't have any charge either, but if we place a charge in the cavity, there must be a charge in the surface to compensate this charge.
In the problem, the outer radius I think is the radius of the sphere and the inner radius the one of the cavity. If we place a charge in the cavity there must be a contrapositive charge to this charge on the surface of the cavity. Hence the charge is negative q, there must be a +q charge in the surface of the cavity. Then we have to compensate to the charge in the outer surface so we need place a q charge. I think that we have to calculate the original net charge on the surface of the conductor and then subtract this q. Therefore, with the result find the new charge density.
Procedure
Q=σ*V
Q=6.67*10^6*(4/3*PI*(0.243)^3
Q=4.008*10^7
so this is the net charge on the surface of the conductor
Qnew=4.008*10^70.870*10^6=4.692*10^7
σnew=(4.692*10^7)/(4/3*pi*(0.243^3)
σnew=2.68*10^7 C/m^2
This is probably very wrong.
I understand that in a electrostatic condition, the net field inside the conductor must be zero otherwise particles would be moving. If we consider a circle with a cavity without charge, i would expect that the surface doesn't have any charge either, but if we place a charge in the cavity, there must be a charge in the surface to compensate this charge.
In the problem, the outer radius I think is the radius of the sphere and the inner radius the one of the cavity. If we place a charge in the cavity there must be a contrapositive charge to this charge on the surface of the cavity. Hence the charge is negative q, there must be a +q charge in the surface of the cavity. Then we have to compensate to the charge in the outer surface so we need place a q charge. I think that we have to calculate the original net charge on the surface of the conductor and then subtract this q. Therefore, with the result find the new charge density.
Procedure
Q=σ*V
Q=6.67*10^6*(4/3*PI*(0.243)^3
Q=4.008*10^7
so this is the net charge on the surface of the conductor
Qnew=4.008*10^70.870*10^6=4.692*10^7
σnew=(4.692*10^7)/(4/3*pi*(0.243^3)
σnew=2.68*10^7 C/m^2
This is probably very wrong.
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