8.19 Consider a current I flowing through a cylindrical resistor of length
L and radius a with voltage V applied. What is the E field inside
the resistor?
L a
J z ϕ × s A. 
B. 
C. 
D. 
E. 
(V/a) z-­‐hat (V/a) ϕ-­‐hat (V/a) s-­‐hat (Vs/a2) z-­‐hat None of the above 8.20 Consider a current I flowing through a cylindrical resistor of length
L and radius a with voltage V applied. What is the B field inside
the resistor?
J J z ϕ × s A. 
B. 
C. 
D. 
E. 
(Iμ0/2πs) ϕ-­‐hat (Iμ0s/2πa2) ϕ-­‐hat (Iμ0/2πa) ϕ-­‐hat -­‐(Iμ0/2πa) ϕ-­‐hat None of the above 8.21 Consider a current I flowing through a cylindrical resistor of length
L and radius a with voltage V applied.
What is the direction of the S vector on the outer curved surface of
L the resistor?
a
J J z ϕ × s A. 
B. 
C. 
D. 
±ϕ-­‐hat ± s-­‐hat ± z-­‐hat ??? And, is it + or -­‐?