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)

 

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