There are two types of circuits that we dealt with in this lab. One type is a RC circuit, which has a power supply, resistor and a capacitor. The other type is a LR circuit, which has a power supply, inductor and a resistor.The first one was a RC circuit. The capacitance (C) of a capacitor is equal to the charge (Q) on either plate divided by the potential difference (VC) between the plates.C Q / VC The capacitance has the units of farads (F). Using Kirchoff’s Loop Rule, we know that The voltage drop across the resistor (VR) plus the voltage drop across the capacitor (VC) equals the voltage rise across the battery (x). This equation looks like:VR + VC = xUsing Ohm’s law and the definition of current we get:VR = IRI = DQ / DtTherefore:VR = (DQ / Dt )RUsing the above information, we can rewrite Kirchoff’s Loop Rule, which looks like:R(DQ / Dt) + (Q / C) = xSubstituting the following variables x and t, we can look at the equation a different way. Here are the definitions of these variables:x Q - xCt RCTo get the charge as a function of time, we use this equationDx / Dt = - x / tBy graphing x versus time, we get the following equation:x = x0 e(-t / t)x0 is the value of x at t = 0. If we replace the x in the above equation with the definition of x, we get:Q = Q (1 - e(-t / t))Substituting the above equation into the equation for capacitance and resistance, we get:VC = x(1 - e(-t / t))VR = xe(-t / t) Since current (I) is VR / R, we can get the equation:I = I0e(-t / t)Discharging a capacitor in a RC circuit can be related to time also. This is seen in the following equation:DQ / Dt = - Q / tRelating this equation to a similar equation that we defined earlier, we can get:Q = Q0e(-t / t)Using the definition of capacitance and Kirchoff’s Loop Rule, we can expand the above equation to these equations: VC = xe(-t / t)VR = -xe(-t / t)Using the definition of current, we get:I = -I0e(-t / t)The other type of circui...
