Magnetic Field of a Current Loop
- The direction of the magnetic field inside and outside a current loop can be found by grabbing the loop with the right hand and pointing the thumb in the direction of the current (CW or CCW).
- The fingers will point in the direction of the magnetic field; opposite directions inside the loop and outside the loop.
Magnetic Field of a Solenoid
- A solenoid is basically a long straight wire bent into a coil of several closely spaced loops (resembles an electromagnet)
- The magnetic field inside the coil is given by: B=
nI
- Where μ0 = 4π x
10^-7 Tm/A
- n = (N/l) = number of turns per unit length
- I = current in Amperes (A)
(source)