Standard Electron Charge To Mass Ratio
The electron charge to mass ratio is a widely known in the scientific field as a value that measures the charge of a standard electron versus its mass. Once the electron is accelerated by a voltage difference the potential energy is then converted to kinetic energy. When an electron is placed into a magnetic field it experiences a force that is perpendicular to the velocity of the electron and the magnetic field. This causes the electron to move in the pattern of a circle, and centripetal force is generated. This tells one that by unit analysis the e/m ratio can be determined by the voltage, magnetic field and the radius of the circle that the electron is traveling in.
Experimental Procedure This experiment was broken down into seven different …show more content…
This can be done by a change in the magnetic field inside of the tube, this can be done by adjust the magnetic field current knob on the power supply. This was done so that the blue beam hit the third ring on the circle and the voltage that was recorded was 91.5V. Once the voltage was recorded the next objective was to find the value of the magnetic field. The current value that went along with circle number three was 3.08A and to find the B value the equation B=(8/sqrt(125))(μ0NI/R) was used. The B value for the third circle was computed to be 3.17x10-3T. The next step in the experiment was the radius for the electron beam, to do this the equation r=(.25x10-2m)(ring number) was used. The r value for ring number three 7.5x10=3m. Once all of the values were found the equation e/m=2V/B2r2 to calculate the electron charge to mass ratio, which was calculated to be 3.24x1011C/kg. When comparing this value to the theoretical value of 1.75x1011C/kg both values are to the same magnitude so the value that was obtained here was sufficient. Once all those calculations were made the same steps were then repeated using the same 100V but this time using ring 2.5 and 2. Once that was done voltage was then lowered to 70V and the rings 3, 2, and 2.5 were all used once again to calculate the e/m
Experimental Procedure This experiment was broken down into seven different …show more content…
This can be done by a change in the magnetic field inside of the tube, this can be done by adjust the magnetic field current knob on the power supply. This was done so that the blue beam hit the third ring on the circle and the voltage that was recorded was 91.5V. Once the voltage was recorded the next objective was to find the value of the magnetic field. The current value that went along with circle number three was 3.08A and to find the B value the equation B=(8/sqrt(125))(μ0NI/R) was used. The B value for the third circle was computed to be 3.17x10-3T. The next step in the experiment was the radius for the electron beam, to do this the equation r=(.25x10-2m)(ring number) was used. The r value for ring number three 7.5x10=3m. Once all of the values were found the equation e/m=2V/B2r2 to calculate the electron charge to mass ratio, which was calculated to be 3.24x1011C/kg. When comparing this value to the theoretical value of 1.75x1011C/kg both values are to the same magnitude so the value that was obtained here was sufficient. Once all those calculations were made the same steps were then repeated using the same 100V but this time using ring 2.5 and 2. Once that was done voltage was then lowered to 70V and the rings 3, 2, and 2.5 were all used once again to calculate the e/m