Podcast
Questions and Answers
What is the primary objective of the electron diffraction experiment?
What is the primary objective of the electron diffraction experiment?
- To investigate the diffraction of electrons from graphite crystals. (correct)
- To study the deflection of light through a prism.
- To analyze the resistance of different materials.
- To measure the electric charge of electrons.
Which equipment is essential for the high-voltage supply in this experiment?
Which equipment is essential for the high-voltage supply in this experiment?
- A high-value resistor of 1 MOhm.
- A digital multimeter for voltage measurement.
- A high-voltage supply unit capable of 0-10 kV. (correct)
- A standard power supply of 120 V.
In terms of lab safety, which of the following protocols is most critical when using the high-voltage equipment?
In terms of lab safety, which of the following protocols is most critical when using the high-voltage equipment?
- Ensuring all connections are insulated and secure. (correct)
- Having a water source nearby for fire safety.
- Wearing cotton gloves.
- Using wooden tools to handle equipment.
When interpreting results from the electron diffraction experiment, what is the primary measurement derived from the data?
When interpreting results from the electron diffraction experiment, what is the primary measurement derived from the data?
Which of the following data analysis techniques is most appropriate for analyzing the diffraction patterns obtained?
Which of the following data analysis techniques is most appropriate for analyzing the diffraction patterns obtained?
What method is used to determine the average radius of the diffraction pattern?
What method is used to determine the average radius of the diffraction pattern?
During the equipment shutdown process, which step should be performed first?
During the equipment shutdown process, which step should be performed first?
Which statement best describes the importance of measuring both inner and outer circles in this experiment?
Which statement best describes the importance of measuring both inner and outer circles in this experiment?
In the scientific reporting of an experiment, how is the radius of the diffraction pattern typically expressed?
In the scientific reporting of an experiment, how is the radius of the diffraction pattern typically expressed?
What is the primary goal of the procedure involving the adjustment of the HV-power supply and the High value resistor during operation?
What is the primary goal of the procedure involving the adjustment of the HV-power supply and the High value resistor during operation?
What is the purpose of adjusting the High value resistor during the experiment?
What is the purpose of adjusting the High value resistor during the experiment?
When recording the radius of electron diffraction, which factors could potentially affect the measurements?
When recording the radius of electron diffraction, which factors could potentially affect the measurements?
What does the calculation of the electron wavelength using de Broglie's equation depend on?
What does the calculation of the electron wavelength using de Broglie's equation depend on?
Which step is crucial to ensure reproducibility in the experimental results?
Which step is crucial to ensure reproducibility in the experimental results?
What could a steeper slope in the graph of radius versus wavelength indicate?
What could a steeper slope in the graph of radius versus wavelength indicate?
Why is it important to repeat the experiment with varying voltage from high to low?
Why is it important to repeat the experiment with varying voltage from high to low?
What does the variable 'd' represent in the interplanar spacing formula?
What does the variable 'd' represent in the interplanar spacing formula?
In order to effectively analyze the data collected, what is a recommended approach to graphing the results?
In order to effectively analyze the data collected, what is a recommended approach to graphing the results?
Which precaution should be prioritized to ensure lab safety during the experiment?
Which precaution should be prioritized to ensure lab safety during the experiment?
What is a likely outcome of incorrectly calculating the radius of electron diffraction?
What is a likely outcome of incorrectly calculating the radius of electron diffraction?
What is the correct alignment of the Helmholtz coil to ensure uniform magnetic field strength?
What is the correct alignment of the Helmholtz coil to ensure uniform magnetic field strength?
In the narrow beam tube setup, what is the purpose of the D.C. power supply?
In the narrow beam tube setup, what is the purpose of the D.C. power supply?
Which adjustment should be made to prevent damage to the cathode during tube operation?
Which adjustment should be made to prevent damage to the cathode during tube operation?
What must be considered when calculating the energy levels of electrons in the narrow beam tube?
What must be considered when calculating the energy levels of electrons in the narrow beam tube?
During the operation of the narrow beam tube, which voltage levels need to be carefully monitored?
During the operation of the narrow beam tube, which voltage levels need to be carefully monitored?
What is the fixed filament voltage used to heat the filament in a narrow beam tube?
What is the fixed filament voltage used to heat the filament in a narrow beam tube?
Which voltage range can be adjusted for the grid voltage in a narrow beam tube?
Which voltage range can be adjusted for the grid voltage in a narrow beam tube?
How is the energy and speed of electrons in the narrow beam tube determined?
How is the energy and speed of electrons in the narrow beam tube determined?
What is the maximum anode voltage available for adjustment in the narrow beam tube setup?
What is the maximum anode voltage available for adjustment in the narrow beam tube setup?
What is the purpose of adjusting the grid voltage in a narrow beam tube?
What is the purpose of adjusting the grid voltage in a narrow beam tube?
In terms of voltage measurement, what instrument is used to measure the voltage difference between the cathode and anode?
In terms of voltage measurement, what instrument is used to measure the voltage difference between the cathode and anode?
When adjusting the narrow beam tube, which condition best represents the anode voltage regulation?
When adjusting the narrow beam tube, which condition best represents the anode voltage regulation?
What general effect does increasing the anode voltage have on the electrons in the narrow beam tube?
What general effect does increasing the anode voltage have on the electrons in the narrow beam tube?
Which adjustment is critical when ensuring that the electron beam maintains a radius of 5 centimeters?
Which adjustment is critical when ensuring that the electron beam maintains a radius of 5 centimeters?
What is the result of increasing the anode voltage while keeping the current through the Helmholtz coil constant?
What is the result of increasing the anode voltage while keeping the current through the Helmholtz coil constant?
What effect does reversing the magnetic field direction in the Helmholtz coil have on the electron beam?
What effect does reversing the magnetic field direction in the Helmholtz coil have on the electron beam?
In the process of adjusting the current in the Helmholtz coil, what optimal limit should not be exceeded?
In the process of adjusting the current in the Helmholtz coil, what optimal limit should not be exceeded?
For measurements at varying radii of 4, 3, and 2 cm, what procedure must be followed?
For measurements at varying radii of 4, 3, and 2 cm, what procedure must be followed?
Which of the following methods is used to record the results of the electron trajectories in the experiment?
Which of the following methods is used to record the results of the electron trajectories in the experiment?
What should the trajectory of the electrons resemble when the circuit is correctly configured?
What should the trajectory of the electrons resemble when the circuit is correctly configured?
Which aspect of the experiment involves manipulating the physical orientation of the narrow beam tube?
Which aspect of the experiment involves manipulating the physical orientation of the narrow beam tube?
Flashcards
Electron Diffraction Experiment Setup
Electron Diffraction Experiment Setup
Arranging electron diffraction equipment as illustrated; including HV-power supply, high value resistor, and electron diffraction tube.
HV-power supply voltage adjustment
HV-power supply voltage adjustment
Adjusting the high voltage power supply to 3 kV to generate electrons from the electron diffraction tube.
High value resistor adjustment
High value resistor adjustment
Adjusting the 3-knob high value resistor to a fixed value determined by the apparatus.
Electron Diffraction Angle Measurement
Electron Diffraction Angle Measurement
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De Broglie Wavelength Calculation
De Broglie Wavelength Calculation
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Graphing Experiment Data
Graphing Experiment Data
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Calculating Graph Slope
Calculating Graph Slope
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Interplanar Spacing Calculation
Interplanar Spacing Calculation
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Experimental Data Analysis
Experimental Data Analysis
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Experimental Report Submission
Experimental Report Submission
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Electron Diffraction Experiment
Electron Diffraction Experiment
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Graphite Crystal
Graphite Crystal
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Interplanar Spacing
Interplanar Spacing
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Electron Diffraction Tube
Electron Diffraction Tube
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High-voltage supply
High-voltage supply
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De Broglie Wavelength Equation
De Broglie Wavelength Equation
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Electron's Kinetic Energy
Electron's Kinetic Energy
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Diffraction Radius Calculation
Diffraction Radius Calculation
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Graph Slope Interpretation
Graph Slope Interpretation
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Cathode Voltage
Cathode Voltage
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Anode Voltage
Anode Voltage
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Grid Voltage
Grid Voltage
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Why is the Cathode Voltage Negative?
Why is the Cathode Voltage Negative?
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Why is the Anode Voltage Positive?
Why is the Anode Voltage Positive?
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Narrow beam tube
Narrow beam tube
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Filament
Filament
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Cathode
Cathode
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Anode
Anode
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Grid
Grid
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Electron acceleration
Electron acceleration
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Electron beam
Electron beam
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Helmholtz Coils
Helmholtz Coils
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Electron Beam Radius
Electron Beam Radius
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Electron Path: Closed Circle
Electron Path: Closed Circle
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Changing Anode Voltage & Current
Changing Anode Voltage & Current
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Electron's Path: Different Radii
Electron's Path: Different Radii
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Reversing Magnetic Field Direction
Reversing Magnetic Field Direction
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Rotating the Electron Tube
Rotating the Electron Tube
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Study Notes
Electron Diffraction Experiment
- Objective: To study electron diffraction from graphite crystals and determine the interplanar spacing of graphite.
Equipment
- Electron diffraction tube assembly
- High-voltage supply unit (0-10 kV)
- High-value resistor (10 MOhm)
- Power Supply (0-600 VDC)
- Vernier caliper (plastic)
- Connecting cords (various lengths and colors, including red, blue, yellow, black, 50, 250, and 750 mm)
Theory
- De Broglie Hypothesis: Matter particles, such as electrons, protons, and neutrons, exhibit wave-like properties. The wavelength (λ) associated with a particle is inversely proportional to its momentum (p): λ = h/p, where h is Planck's constant.
- Electron Wavelength Calculation: The wavelength of an electron accelerated through a potential difference (U) is given by: λ = h / √(2meU), where m is the electron mass and e is the electron charge.
- Bragg's Law: When electrons are diffracted by a crystal lattice, constructive interference occurs when the path difference between waves scattered from different planes is an integer multiple of the wavelength. This is expressed by Bragg's Law: 2d sin θ = nλ, where d is the interplanar spacing, θ is the Bragg angle, and n is an integer.
- Graphite Crystal Structure: Graphite consists of layers of carbon atoms arranged in a hexagonal lattice. The interplanar spacing (d) within the layers is a key property for diffraction analysis.
Procedure
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Setup: Assemble the equipment according to a diagram (figure 3).
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High Voltage Adjustment: Set the high-voltage power supply to 3 kV, and adjust the high-value resistor according to the instrument's specifications.
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Electron Diffraction Measurement: Vary the accelerating voltage from 3 kV to 7.5 kV in steps of 0.5 kV. Measure the radii (r) of the diffracted electron rings for each voltage. Repeat measurements for decreasing voltages (7.5 to 3 kV).
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Data Recording: Record all measurements of radii for each voltage.
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Graphing: Plot radius (r) versus wavelength (λ) to obtain a graph. The slope of this graph (A) represents a value related to the interplanar distance and can be used to calculate that parameter.
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Calculating Interplanar Spacing (d): Using the slope from the graph and the equation (2R/A), determine the interplanar spacing (d) from the experiment's equipment and setup (Where R represents the radius of the circular screen).
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Analysis and Conclusion: Analyze the results, discuss observations, and explain any discrepancies. Address the question of whether the graphite used is single-crystalline or polycrystalline.
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Description
This quiz covers the principles and equipment used in the electron diffraction experiment aimed at exploring the interplanar spacing of graphite crystals. Key theories such as the De Broglie hypothesis and Bragg's Law will also be assessed, emphasizing the wave-particle duality of matter. Prepare to test your understanding of the concepts and calculations involved in this detailed experiment.
