• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11
  12. 12
    12
  13. 13
    13
  14. 14
    14

Charge To Mass Ratio For An Electron

Extracts from this document...

Introduction

Physics Formal Lab Charge To Mass Ratio For An Electron Professor: Dr.Kilner Ta: Mr.Laderman Done by: Amir Mofidi 010238350 Section 004 Abstract How electrons behave in the presence of a magnetic field was the purpose of this lab. In particular, how there is a force acting on the electron in a magnetic field related to its velocity; or in other words the force acting on the electrons will cause them to move in a circular path. Measuring the charge to mass ratio of an electron using an apparatus which fires electrons into a uniform magnetic field produced by Helmholtz coils; the particles follow a circular path. The anode voltage was set at 200v; the radius of the curvature of the electrons was changed by adjusting the Helmholtz coils current. Its radius ranges from 11cm to 6 cm; the strength of the magnetic field and the speed of the moving particles, one can figure out the charge to mass ratio. The value found for the ratio of electrons to mass to in this experiment would be 1.89�1011 coulombs/kg. Comparing this experimental value to the theoretical value which is 1.76�1011 coulombs/kg makes a 7.38% experimental error. ...read more.

Middle

To observe the circular motion of an electron beam in a nearly-uniform magnetic field and deduce the charge-to-mass ratio of the electron from measurements of the orbital radius. Based on theoretical calculations and experimental evidence, both the charge and the mass of an electron are constants, as is the ratio of the two. The magnetic field will induce a force on the electron which is perpendicular to both the direction and the magnetic field, and will force the electron beam to curve. The radius of curvature can be used to calculate the charge-to-mass ratio, since the curvature is directly related to both the mass of the electron and its charge. Method In this experiment the equipments were set up as in figure3. Figure 3 At the base of the e/m apparatus are inputs for the heater filament voltage (the cathode from which the electrons will be emitted), the anode voltage (the voltage through which the electrons will be accelerated), and the Helmholtz coil current. 6 volts from the output of the power supply was applied to the heater inputs located on the base of the e/m apparatus. The discharge tube power supply was turned on and the cathode glow red hot. ...read more.

Conclusion

It is fair to say that this simple experiment sparked a line of research which drastically changed our way of thinking about the universe. Aside from the thrill of repeating an important and historic experiment, this lab is an ideal forum for exploring the motion of charged particles in electric and magnetic fields. At the end of the day, it is to be known how to calculate the electromagnetic force on a particle in any field configuration. Conclusion In this experiment you will observe the behavior of electrons in a magnetic field and determine a value for the electron charge-to-mass ratio e/m. Although it ended up with a 7.38% error it is still an acceptable value for this experiment. The final observed value for e/m turned out to be 1.89�1011 coulombs/kg. Considering the inherent difficulties associated with the experiment, the results are astonishingly accurate. One difficulty was accurately measuring the radius of the beam on the ruler due to that the room was not dark enough and it made it hard to see the exact radius of the beam. Second the Helmholtz coils where not orient parallel to the direction of the earth's magnetic filed (about 15? east of geographic north); so the effect of the earth's magnetic filed was not minimized and it had its effects in this experiment. At the end it was very interesting lab with very good results. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Fields & Forces section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Fields & Forces essays

  1. Peer reviewed

    Investigating the forces acting on a trolley on a ramp

    5 star(s)

    However, it is very unlikely to be the only source of error in the experiment. In the following section, errors will be discussed and a new value of g will be calculated, this time taking friction into account. While this provides a more suitable value for g, the error that

  2. The experiment involves the determination, of the effective mass of a spring (ms) and ...

    Hence the order of the readings. Main Readings Mass/Kg x number of oscillation's Time for x oscillations ( in seconds) xT av/s T/s T2/s2 ?xT/s % unc in xT % unc in T2 ?T2/s2 0.100 0.200 0.250 0.300 0.400 0.450 0.500 0.600 50 40 35 30 25 30 25 25

  1. Investigating a factor affecting the voltage output of a transformer.

    Preliminary work Firstly I wanted to determine what distance between the primary and secondary coils gives the optimum conversion of primary voltage to secondary voltage. As shown in the table below, this distance is 0cm. Secondly I wished to know what the best range of nominal voltages is.

  2. Investigation to determine the viscosity of glycerol.

    * Measuring Cylinder - will be filled with glycerol. The ball will be dropped into the measuring cylinder after filling it with glycerol. The measures on the cylinder will help me calculate the velocity of the ball between two marked points on it. * Thermometer - is used to determine the temperature of glycerol at any given time.

  1. Modeling a basketball shoot in the lab

    How to model a basketball shot? The general idea of this experiment is to give a constant force on a ball at a certain angle, aiming to land on a sand pit as follow. Figure 3. The general experimental set up Apparatus - - Spring loaded plunger - A 'run way' - Lab Jack - Clamp

  2. Einstein's theory of relativity.

    They measured the effect of altitude on the frequency of gamma rays. Many scientists are doing research in general relativity and studying possible improvements on Einstein's theory.

  1. What Affects the Strength of Magnetism Exerted By an Electromagnet?

    This will consequently increase the influencing lines of flux and the power of magnetism.' Putting this hypothesis into action through the experiment; more paperclips should be attracted and lifted against their weight as the voltage is increased. However, as the power supply increases the current with the voltage, there should not be direct proportion in the results collected.

  2. To investigate the effect of current on the strength of an electromagnet field.

    6 Volts Current (A) Mass (g) 0.2A 4g 0.4A 5g 0.6A 9g 0.8A 11.5g We decided to increase the range of current readings by increasing the voltage to 9V. This gave us a current range of 0A to 2.7A. This would give us 8 readings increasing in 0.3A intervals.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work