If a long hollow copper pipe carries a direct current, the magnetic field associated with the current will be
a) Only inside the pipe
b) Only outside the pipe
c) Neither inside nor outside the pipe
d) Both inside and outside the pipe
If a long hollow copper pipe carries a direct current, the magnetic field associated with the current will be
a) Only inside the pipe
b) Only outside the pipe
c) Neither inside nor outside the pipe
d) Both inside and outside the pipe