Physics 30 June 01 Diploma Exam

Physics 30 June 01 Diploma Exam

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Unformatted text preview: ates magnetic field perpendicularly into the page Oppositely charged parallel plates Analysis: Fe = Fm or balanced forces V E q = Bvq, E = 2 d V2 B= dv Special Notes: Method 2 • The method of determining the speed of the electrons must be explicit • The electron path and magnetic field must be perpendicular • The polarity on the power supplies must be consistent to accelerate the electrons and to produce an electric force in the opposite direction to the magnetic force • The direction of F , F and B must be consistent m • e The method of determine the position of the electron beam does not need to be practical. For example, it is not necessary for the student to explicitly identify how the electron path is observed. 6 Method 3 – Generator List: voltmeter Wire (or metal rod) ruler stopwatch or speed measuring devices Procedure: • measure length of wire (or rod) in the magnetic field • connect voltmeter across both ends of wire (or rod) • move wire (or rod) perpendicularly through the magnetic field at a uniform speed • determine speed using a measured distance with ruler and corresponding time interval with timer or use a speed measuring device • record induced voltage Fm A Fg N Analysis: S Variable power supply V = vlB and v = d/t B = V/vl Special Notes on Method 3 • timing devices may include radar gun, sonic ranger, stop watch • the length of the wire (or rod) in the magnetic field must be measured • the wire (or rod) must be moved perpendicular to the magnetic field 7 Method 4 – Current Balance 1 List: ammeter balance variable power supply wire (or rod) meter stick Procedure: • measure mass of wire or metal rod that will be levitated by the field • measure perpendicular length of magnetic field (This is the length of conductor in the magnetic field.) • complete a circuit with the variable power supply, the wire or metal rod and the ammeter all in series • place the wire or rod perpendicular to the magnetic field • adjust the current until the wire or metal rod is suspended in the magnetic field • record current Fm A Fg N S Variable power supply Analysis: Fm = Fg BIl = mg mg B= Il Special Notes: Method 4 • • • • The length of the wire or metal rod in the magnetic field must be measured The mass that will be lifted must be measured The wire or rod must be perpendicular to the magnetic field the direction of Fm must be opposite gravity and consistent with the polarity of the power supply (i.e. the electron flow must be into the plane of the page through the wire) 8 Method 5 – Current Balance 2 List: ammeter balance wire or metal rod metre stick variable power supply string Procedure: • measure mass of wire or metal rod • measure perpendicular length of magnetic field (This is the length of conductor in the magnetic field.) • suspend the wire or rod from one arm of the balance • connect wires, rod, power supply and ammeter in series • zero the balance • adjust the current, record current • read the change in mass measured by the balance Fm N S A Variable power supply Analysis: ∆ weight = Fm ∆ m ⋅ g = BIl ∆m ⋅ g B= Il Special Notes: Method 5 • • • The length of the wire or rod in the magnetic field must be measured The...
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This note was uploaded on 01/14/2014 for the course PHYSICS Physics 30 taught by Professor Quinlan during the Fall '09 term at Centennial High School.

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