Right-Hand Rule #2

         Through Oersted's principle three basic "right-hand rules" for determining conventional current flow when dealing with electromagnetism were created. While the first right-hand rule is used for conventional current flow through straight conductors, the second right-hand rule is used for understanding the direction of the current of electromagnetic force through coiled conductors (1). The 2nd right-hand rule can be understood and explained in the following 10 steps.

1. You must note that because the current travels through a coil, charge enters through the negative terminal from one end of the wire and flows in a circular fashion through the coil to exit from the positive terminal on the opposing end of the wire. 
2. Due to the conductor being coiled the field is generally strengthened because the individual field lines fall on top of one another (1)

3. First, you must grasp the coiled conductor with your right hand (1).

4. Your curved fingers must point in the direction of conventional flow (the flow of current from the positive terminal to the negative terminal) (1).

5. The direction of the magnetic field within the coil will equal the direction in which your thumb is pointing (1).

6. The thumb serves as the north (N) end of the electromagnet created by the coil in this example (1).

7. The current in the coil varies directly to the field strength (1).

8. The number of turns in the coil also varies directly to the field strength (1).

9. The magnet's strength varies directly to the use of ferromagnetic materials within the coil (1).

10. The size of the coil has an inverse relationship with the strength of the magnetic field (1). As the size increases, the strength decreases (1).

 

         Figure A demonstrates the 2nd right-hand rule in use (2); clearly showing the direction of the thumb as well as how the fingers surround the coil thus displaying the current direction with ease. 

Figure A

References

(1) Heimbecker, B., & Nowikow, I. (2001). Physics: Concepts and connections. Toronto: Irwin Publishing Ltd.

(2) New Physics at Work : Student's Corner. (n.d.). Oxford Science City. Retrieved February 27, 2012, from http://sciencecity.oupchina.com.hk/npaw/student/glossary/right_hand_grip_rule.htm