Physics 109 - Resonant Circuits Part I |
Today's lab starts with another invention activity. A data set for working with the inventiona activity can be found HERE.
Once you have completed the
invention activity we will have a short lesson. if you are done before
the lesson, start assembling the circuit below.
After the lesson, you will use last week's data to do an unweighted fit AND an esyimated unsertainty in the slope
A resonant circuit: One of the most common models for
physical systems is the harmonic oscillator. A classic example
is mass on a spring. When you give the mass a sudden push it oscillates
at some natural frequency and those oscillations gradually die
away until the next push. Today you will study an electronic version
of this - the series combination of an inductor, a resistor and
a capacitor (LRC). After your instructor has outlined how to build
this circuit, go ahead and assemble one yourself. The 'kick' you
will be giving to the circuit comes by driving it with square
waves from your function generator, set to about 100 Hz. You'll
see the response of the circuit on your oscilloscope.
Measure the amplitude of the oscillations as a function of time, all the way to the point at which the oscillations have disappeared into the electrical noise (do not use the averaging mode of the oscilloscope, since we want you to see the impact that noise has on your measurments and data analysis).
Marking Scheme
participation in invention activity: 2 marks
Graph and unweighted fit to last week's data, including uncertainty in the slope: 3 marks
comparison of slope and uncertainty to the expected value of the capaciatance: 1 mark
LRC data taking:
circuit diagram, description of data-taking method, and justification
of uncertainty estimates: 3 marks
linearized plot of amplitude versus time: 3 marks