Do our GCSE and A-level physics tutor lessons go far enough into the actual physical mechanism of current flow through electrical conductors (in charge carriers and electric fields)? I hate to admit it, but I think the answer is no more and more. When pressed, can we explain, for example, why a bulb almost instantly lights up when a switch several kilometres away is closed when the charge carriers can be demonstrated to move at speed comparable to that of a leisurely jogger? Of course, as physics teachers, we speak with apparent confidence of current, potential difference, and resistance. This new system is expected to benefit both students and universities. Students will be able to save thousands of dollars each year, while universities will also receive a boost in their reputation. A qualified physics tutor can explain concepts in physics clearly and understandably.
This would suggest tens of minutes delay between flipping the switch closed and energy being delivered to the lightbulb (through the charge carriers). When students questioned me about it, I tended to give one of the following answers: “Energy is being transferred to each charge carrier via the electric field from the power source,” or “Energy is being transferred to each charge carrier via the electrons in the wire are repelling each other so when one close to the power source move, then they all move.” Honestly, I don’t believe such answers are enough because they are too tentative and “hand-wavy.” A physics tutor may also help you with admission examinations, assessments, and other examinations. When it comes to getting your children into prestigious schools, scoring well in school examinations isn’t always enough. Our pay depends on our abilities and experience. Better people get better pay.
And I don’t like being that well-intentioned but incredibly condescending physics teacher who ends exciting conversations with a wide-eyed “Oh, you’ll understand that when you study physics at degree level.” According to Sherwood and Chabay (1999), a method for circuit analysis based on a primarily classical model of electrostatic charges interacting with electric fields is particularly beneficial. According to this theory, the moving electrons exert forward pressure on one another, much like nearby water molecules would exert pressure on one another through a hose. Since every negatively charged electron repels every other negatively charged electron, if a free electron moves in a conductor, the nearby free electrons will likewise move.