The Magnetic Field of a Solenoid - Memorial · PDF filePhysics 1051 Laboratory #5 Magnetic Field of a Solenoid Part III:Apparatus and Setup The Magnetic Field Sensor The magnetic field

Physics 1051 Laboratory #5 Magnetic Field of a Solenoid
The Magnetic Field of a Solenoid

Contents
Part I: Objective Part II: Introduction Magnetic Fields in Current Carrying Wires The Solenoid The Ideal Solenoid The Real Solenoid
Part III: Apparatus and Setup Apparatus Setup Details The Magnetic Field Sensor LoggerPro
Part IV: The Experiment Using the Magnetic Field Sensor Magnetic Field of a Solenoid Prediction of the Field as a Function
of Current Magnetic Field as a Function of
Current Plotting Data Analysis Part V: Summary

Part I: Objective
The primary objectives of this experiment are: To investigate the magnetic field of a solenoid to determine if a
current carrying slinky is an ideal solenoid. To find the dependence of the magnitude of magnetic field B a
the centre of a solenoid on current I.

Part II: Introduction Magnetic Fields in Current Carrying Wires
When current is passed through a conductor, a magnetic field is produced. The magnetic field vector may be determined using the Biot-Savart law.
Magnetic field is a vector and has units of tesla (T).

Part II: Introduction The Solenoid
A solenoid is composed of a number of turns of a conducting material, arranged in a cylindrical fashion. Solenoids are commonly used in electronic circuits, and electromagnets. A Slinky is a good example of a solenoid. Current passing through the Slinky creates a magnetic field inside the solenoid.

Part II: Introduction The Ideal Solenoid
For an ideal solenoid, the magnetic field is produced completely inside the solenoid and is constant along the length. The field produced inside a solenoid is parallel to the axis as shown.
The field inside an ideal solenoid with turns N, length L, and current I may be calculated from Amperes law and has magnitude
where o is the permeability of free space with value 410-7 Tm/A .
B =oNI
L

Part II: Introduction The Real Solenoid
For a real solenoid, magnetic field is not constant at the ends and some field exists outside the solenoid.

Part III: Apparatus and Setup Apparatus
You have been provided with:
Slinky Metre stick Power supply Leads with
alligator clips Magnetic field
sensor (one of two)
Clips

Part III: Apparatus and Setup Setup details
You may find it useful to attach the slinky to the metre stick using the silver clamps.
The alligator clips may be used to hold the slinky to the clamps.

Part III: Apparatus and Setup Setup details
Leads may be connected from the alligator clips to the power supply.

Part III:Apparatus and Setup The Magnetic Field Sensor
The magnetic field sensor uses a Hall effect transducer to measure the magnetic field.
The magnetic field sensor should be plugged into Channel 1 on the LabPro.
Set the switch on the sensor to either LOW or to 6.4mT.
The sensor measures magnetic fields parallel to the normal of the white dot on the tip of the sensor.

Part III:Apparatus and Setup LoggerPro
Launch the LoggerPro program by clicking on the icon below.
To take measurements: ! Turn the power supply on and adjust the voltage and current dials until
you have the desired current (to a maximum of 2.0 A). ! Turn the power supply off. ! Insert the magnetic field sensor at the location you wish to measure the
field. ! Click the Experiment then Zero (to zero contributions from the Earths
field and surroundings). ! Wait 5 seconds to ensure the field is truly zeroed. ! Turn the power supply on.
You will repeat each of these steps in this order before all data collection.

Lab Report
Lab Report 1: Write the objective of your experiment. Lab Report 2: Write the relevant theory of this experiment. Lab Report 3: List your apparatus and sketch your setup.

Part IV: The Experiment Using the Magnetic Field Sensor
Goal: Take a set of measurements of the magnetic field inside the
solenoid in order to determine the orientation and magnitude of the magnetic field.
The sensor measures magnetic fields parallel to the normal of the white dot on the tip of the sensor.

! Place the magnetic field sensor inside the solenoid at the midpoint.
! Zero the sensor with the power turned off.
! Set the current (maximum of 2.0 A).
! Measure the magnetic field in the following positions:
- white dot facing the negative terminal
- white dot facing the positive terminal
- white dot facing the ceiling
- white dot facing the floor

Lab Report 4: What direction is the white dot on the sensor pointing, relative to the axis of the solenoid, when the largest positive field measurement is registered? Specify if it is perpendicular or parallel to the axis and which terminal the white dot is facing.
Perpendicular to the axis means that the white dot is facing either the ceiling or the floor. CHECKPOINT: Have an instructor come check your setup and results and sign your lab report.

Part IV: The Experiment Magnetic Field of a Solenoid
Goal: Determine the relative magnitude of the magnetic field
- along the length of the solenoid - at the ends of the solenoid - just outside the solenoid
Sensor position: For your measurements, you will hold the sensor so that it is facing the direction as stated in the answer to Question 4.
Place the magnetic field sensor inside the solenoid at the midpoint. Zero the sensor with the power turned off. Set the current (maximum of 2.0 A).

Use your magnetic field sensor to determine the magnetic field at the points listed above:
You may find the average magnetic field by clicking Analyze then Statistics.
along the length of the solenoid Insert video along_the_length.mp4
here
Click arrow to play video

at the ends of the solenoid Insert video at the ends.mp4
here

just outside the solenoid Insert video just_outside.mp4
here

Lab Report 5: From your results, describe the magnetic field of a solenoid.
You may wish to include the answers to the following questions:
Is the magnetic field constant along the length of the solenoid?
Is there variation at the ends? Is the field weaker (or zero) outside the solenoid? Lab Report 6: Can your solenoid be considered ideal? Explain.

Part IV: The Experiment Prediction of Field as a Function of Current
Goal: Predict and test how the magnetic field at the centre of a solenoid depends on the current running through it.
Lab Report 7: How do you expect the magnetic field at the centre of
a solenoid to depend on current? Explain.

Part IV: The Experiment Magnetic Field as a Function of Current
A maximum current of 2.0 A is recommended for this part of the experiment.
Use your magnetic field sensor to obtain a set of data for the magnetic field inside the solenoid as a f

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The Magnetic Field of a Solenoid - Memorial · PDF filePhysics 1051 Laboratory #5 Magnetic Field of a Solenoid Part III:Apparatus and Setup The Magnetic Field Sensor The magnetic field