The fridge in your secret zombie apocalypse hideout is creating an electric field. Crud! You are...

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The fridge in your secret zombie apocalypse hideout is creating an electric field. Crud! You are anxious about someone detecting it (and you). Killing time, you are rereading your PHYS 272 notes (that happened to be on your shelf all this time) and you've realized that enveloping you fridge inside a hollow conductor might mask its field. You find some leftover metal plates and build a box around the fridge. (The fridge has some arbitrary charge Q.). Q a) Show, using Gauss's Theorem, that the electric field outside the box must be non-zero. Draw a Gaussian surface outside the box to prove this point. b) You suddenly remember our discussion about electrical grounds and hook up the metal box to a rod inserted into the Earth (aka grounding). Why is the electric field outside the box now zero? Draw the charges and a Gaussian surface to illustrate your point. This is an inverse of a Faraday cage. (The inside of a Faraday cage is shielded from electric fields outside. Ex. Lightning suit shielding a person from massive external charges.) The fridge in your secret zombie apocalypse hideout is creating an electric field. Crud! You are anxious about someone detecting it (and you). Killing time, you are rereading your PHYS 272 notes (that happened to be on your shelf all this time) and you've realized that enveloping you fridge inside a hollow conductor might mask its field. You find some leftover metal plates and build a box around the fridge. (The fridge has some arbitrary charge Q.). Q a) Show, using Gauss's Theorem, that the electric field outside the box must be non-zero. Draw a Gaussian surface outside the box to prove this point. b) You suddenly remember our discussion about electrical grounds and hook up the metal box to a rod inserted into the Earth (aka grounding). Why is the electric field outside the box now zero? Draw the charges and a Gaussian surface to illustrate your point. This is an inverse of a Faraday cage. (The inside of a Faraday cage is shielded from electric fields outside. Ex. Lightning suit shielding a person from massive external charges.)

Answer rating: 100% (QA)

a According to Gausss Theorem the electric flux through a closed surface is equal to the charge enclosed divided by the permittivity of the medium If ... View the full answer