Question

Question with multiple parts; please help.

1. a) The SI unit of charge is the coulomb and the SI unit of capacitance is the farad (F). What do we mean when we say these units are "ridiculously large?"

b) Explain why the electric field at the surface of a conductor must be perpendicular to the surface.

c) Use Gauss's law to explain why any excess charge on a conductor must lie on the surface.

d) Explain physically (no equations) why inserting a dielectric in the gap of a parallel plate capacitor increases the capacitance.

e) A current loop with magnetic dipole moment is placed at the center of a dodecahedron. What is the total magnetic flux through the surface? Explain. Can this information be used to calculate the magnetic field?

f) Explain why there is no net force on an electric dipole in a uniform electric field.

g) Explain why a magnetic field can exert a force on a current carrying wire. You can use equations if necessary.

Answer 1

A :- 1 Coulomb charge means approx 1/e = 6 ×10¹⁸ electrons . As we know that charge be transfer by electrons and to charge any body by 1 Coulomb we have to transfer 6 × 10¹⁸ electrons which is really a very large quantity thats why 1 Coulomb charge is very large

Capacitance given by Q/V for 1 F capacitance we have to transfer approx 1 Coulomb charge for 1 volt potential difference so 1 F is also a large quantity.

B :- as we know that conductors be equipotential surfaces so if there is any nonzero tangential component then we have to work done to move from one of surface to another point thus way there would be a potential difference which is a contradiction so electric field always be perpendicular to the conductor surface.

C :- Gauss law states that electric flux passing through a closed surface be equal to the

( 1 /epsilon not ) times to total enclosed charge .

Since there is no electric field inside a conductor so there must be charge in volume equal to zero.

D:- AS We insert a dielectric slab inside the capacitor capacitance increases because we have to pump more charge on plates of capacitor because some part of the field get cancel out because of induced charge in slab . So for the same potential difference after inserting the slab we have to pump more charge is the reason of increment in capacitance.

According to Chegg policy we are supposed to solve only first 4 parts of the problem. But still if you have any doubt mention in comment i will explain