PHYSICS LABORATORY 2 (UNIT 2)
Learning outcomes of the course unit
It is expected that at the end of the course the student will be able:
1) to discuss deeply concepts of optics and of electromagnetism in the light of the achieved experimental verifications of phenomena;
2) to recognize and identify phenomena of electromagnetism and optics and to set up autonomously an experience, by checking systematic errors and critical issues;
3) to analyze data correctly and to describe the experiment carried out in a report with a correct scientific language;
4) to synthesize and link related experiences;
5) to propose customized approaches or in-depth analysis of one or more experiments (among those proposed), based on one's own interest and curiosity;
6) to have acquired manual skills in the use of electronics and optics;
7) to have understood more deeply the concepts of electromagnetism, by relating phenomenon and formal description of the phenomenon;
8) to know the basic principles of geometric optics, sources and detectors of light, electronic noise and any argument that is peculiar of the course.
Attendance of the courses: Physics Laboratory 1 and the first modulus of Physics Laboratory 2.
Course contents summary
Electromagnetism and optics experiments.
• Electronic noise (specific topic of the course). Noise sources. Spectrum of noise and its measure. Noise control and possible sources of systematic errors.
• The Faraday law. Summaries of theory: magnetic field generated by a loop, induced current; the Earth's magnetic field. Presentation of experiences: measurement of induced current in a loop, measurement of the magnetic field of a loop, of the local terrestrial magnetic field, of the horizontal component.
• Response to the electric field. Summaries of theory: electrical conductivity and Hall effect. Measurement of Hall coefficient and electronic mobility. The gaussmeter. Presentation of experiences: measure of resistivity and Hall coefficient in a material.
• Summaries of theory on electromagnetic waves and properties.
• Light sources (specific topic of the course): operating principle (incandescent, discharge lamps, LASER) and the properties of the emitted radiation.
• Light detectors and operating principle (specific topic of the course): thermal and photonic detectors, photodiodes, photo tubes, photomultipliers, bolometers.
• Geometric optics (specific topic of the course). Snell's laws. Reflection-refractive images from flat surfaces and curves. Spherical mirror and spherical diopter. Lenses, lens systems, aberrations. Dispersion. Presentation of experiences: measurement of the focal length of reflective and refractive centered optical systems, estimation of the transverse magnification. Calibration of a prism spectrometer.
• Polarization and polarization methods: summaries of theory. Dichroic and birefringent films. Presentation of experiences: Verification of Malus Law, determination of Brewster's angle of a material and derivation of the refractive index.
• Physical optics. Summaries of theory: spatial and temporal coherence. Interference and diffraction. Interference from single and multiple slit. Diffraction grating. Transmission and reflection diffraction gratings. Presentation of experiences: double-slit interference, Michelson interferometer, reflection and transmission pattern characterization, acquisition of the emission spectrum of incandescent and discharge lamps by a diffraction-grating spectrometer. Colored filters.
• Wavelength measurement methods (specific topic of the course): comparison of dispersive and interferential systems. Solving power and dispersing power. Critical analysis of the possibility of solving the doublet of sodium through the experimental sets used in the couse.
Topics covered in the course are presented by emphasizing the phenomenological aspects of geometrical optics, physical optics and some aspects of electromagnetism, giving priority to issues inherent in the experimental verification of the physical laws discussed. Lectures will include a brief introduction on the relevant theory of optics and electromagnetism followed by experiments of laboratory, discussion of experimental results and in some cases discussion of written exercises. Each experiment will be accompanied by written reports.
Lecture notes for the lesson topics, lab-guide sheets for experiments, and the detailed calendar of activities are provided by the teacher: all the teaching material is available on the Elly platform at the beginning of the course. Slides of lessons in pdf format are included. Some texts are also suggested, which can be consulted in the department library.
Assessment methods and criteria
The exam requires the preliminary submission of the reports on the experiences made during the course and consists of an individual practice test, a brief written text (with practical-application questions with open-answer) and an oral test.
The oral test expects the discussion of a few topics proposed in the text, of issues dealed in the course (in particular the specific topics of the cource), with particular attention to the subject matter of the practice test.
Skill of critical comment on experiment relationships are required.
The final evaluation is based on: the experimental relationships [20%]; the practical test carried out (to test the autonomy in the execution of an experiment) [20%]; knowledge, critical sense and appropriate scientific language shown in the oral text (and brief writtten text) [60%].
To pass the exam the student must have participated in 80% of the experiences; he must have delivered the reports, partecipated in the mentioned tests, showing, in particular, sufficient understanding of the topics during the oral exam.
The duration of the written test will be one hour; the duration of the individual practical test will be two hours and will require the presentation of the collected data, with calculation of the error and annotation of the criticality of the experiment, but without drafting a report. The results will be discussed during the oral exam. The oral exam will last approximately 40 minutes.
For the preparation of the test a facsimile of possible questions is provided. The written test constitutes a self-assessment test and a study guide for the student and is valid for the final evaluation only if successful. The incorrect answers will be discussed during the oral examination.
The practical test aims to highlight the individual ability to set up an experiment and concerns a significant aspect of one of the experiences carried out by the student during the year, made known to the student the day before the test itself. During the test the student will interact with the teacher to explain the crucial details for the good conduct of the experiment and will be able to consult the lecture notes. The result of the test will be declared immediately at the end of the test.
Participation in at least 80% of laboratory experience is mandatory. In case of longer absence, recovery days are organized at the end of the course. Under particular conditions (for example, in the case of working students) the opportunity to carry out personalized courses can be assessed.