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Physics 202 (College Physics)Laboratory Exercise (9)The Magnetic Field in a CoilEquipment needed:Computer, DC Power SupplyVernier computer interface Logger Pro, Vernier Magnetic Field Sensor, Mailing or poster tube, 4–10 cm diameter, with a hole drilled for the sensor, magnetic compass, long spool of insulated wire (at least 1 m)Introduction:When an electric current flows through a wire, a magnetic field is produced around thewire. Themagnitude and direction of the field depends on the shape of the wire and the directionand magnitude of the current through the wire.A solenoidis a long coil of wire consisting ofmany loops (or turns, N) of wire. A solenoid act like amagnet: one end can be considered the North pole, and theother the South pole, depending on the direction of thecurrent in the loops.For an ideal solenoid shown in Figure 1 themagnetic field Binside a tightly wrapped solenoid withnumber of turnsN, lengthL, each carrying current Icanbe calculated from Ampere’s law and has magnitudeFigure 1B=μ0L∋¿where:μ0– the permeability constant = 4π × 10–7[T·m/A], Objectives:1.In this experiment, you will examine how the magnetic field is related to both thecurrent I through acoil and the number of turns N in a coil.2.A Magnetic Field Sensor will be used to detect the magnetic fieldB atthe centerofthe coil.3.The sensor will also detect the Earth’s fieldand any local fields due to electric currentsor some metals in the vicinity of the sensor.4.To ensure we are measuring the field we intend to, being the magnetic field generatedby the solenoid, there is a particular process that must be followed. Initial Setup:1.Using the long spool of wire, loop the wire 10 times around the end of the tube with the hole, creating a coil of 10 turns. The coil should be next to, but not cover, the hole.
2.Bend the tip of the Magnetic Field Sensor so the tip is perpendicular to the shaft of the sensor, as shown in Figure 2a. The sensor measures magnetic fields parallel to the