Hi all Please Register or Log in to view the hidden image! im a first timer here! i was wondering if anyone could help me......im stuck on a question for my uni assignment and ive racked my brains for the last coupla hrs without any sucess..... and ive never been great at physics..... One of the few remaining types of vacuum tube in common use is the cavity magnetron which is used in microwave ovens. In this device, microwaves are generated by electrons held in circular orbits by a magnetic field. For electrons with mass me (in kilograms, kg) and charge e (in coulombs, C) moving with speed ν (in metres per second, m s−1) in a magnetic field of strength B (in teslas, T, which is the SI unit of magnetic field strength), the radius of the orbit, r (in metres, m), is given by: mv r =eB (i) Rearrange Equation 1 to make B the subject of the equation. Use your answer to (i) to express the SI unit of magnetic field, the tesla, as a combination of SI base units. Use letters and symbols to represent all units, and be sure to show all your working. (Note that the ampere, A, is an SI base unit, but the coulomb, C, is not.) my answer to (i) was - B = (mₑv ÷ e) r not sure if thats correct or not..... but it does not have these units in my book, and there has been no mention of magnetic field or tesla either...... so if anyone could shed any light it would be HUGELY appreciated!! as im at the end of my tether now and feel like giving up...... Ax
\(mv^2/r=eBv\) so: \(mv/r=eB\) \(B=mv/(er)\) In SI units: \(T=kg/(Coulomb*sec)\) The answer agrees with the Tesla (T) definition.
thanks so much for the help Please Register or Log in to view the hidden image! greatly appreciated....ty Ax
