Physics Lab Circuit Construction

V=IR P = I V = I2 R = V 2 / R Req = R1 + R2 + R3 1/Req = 1/R1 + 1/R2 + 1/R3 Pull up the simulation, and click on Intro box Circuit Construction Kit: DC – Series Circuit | Parallel Circuit | Ohm’s Law – PhET Interactive Simulations (colorado.edu) Click on Values on the upper right, and then on the lower left, the Battery symbol Drag the components on the left (battery, resistor and then 2 wires) to build the circuit shown below. This first circuit to construct is a simple “series, resistor-battery circuit”. Tap the center of the resistor circuit symbol, to change its resistance, to 11 Ω. Once done, you’ll see the electrons going around the circuit, from the – terminal of the battery. Pull the voltmeter and ammeter into place as is shown. The ammeter measures current to 2 significant figure accuracy, while this lab has you doing calculations to 3 significant figures. Here, for example, the ammeter reads I = .82 A, when V = I R gives I = V / R = .818 A Finally click under Show Current, “Conventional” and the current circulates opposite to the blue electrons, coming out from the + terminal of the battery with red arrows. Click the lower-right reset button, and the Values and Battery symbols for our next circuit. 1. Resistors in Series. Construct the circuit to the left, with resistor values as is shown. R1 = ____ Ω. R2 = ____ Ω. Req = ____ Ω (calculate) V = ____ V. I = ____ A (calculate to 3 sig figs). 2. Resistors in Parallel. Construct the circuit to the left. R1 = ____ Ω. R2 = ____ Ω. Req = ____ Ω. (calculate to 3 sig figs) V = ____ V. I = ____ A (calculate to 4 sig figs). 3. Resistors in Series and Parallel combination Construct the circuit to the left. R1 = ____ Ω. R2 = ____ Ω. R3 = ____ Ω. Req = ____ Ω (calculate, 3 resistor combination, to 4 sig figs) V = ____ V. I = ____ A (calculate to 4 sig figs). Final notes. Batteries have unequal lines in their symbols. The longer line is always the + terminal. Wires cause no potential drop, meaning the voltage is the same at any two points in a circuit simply connected by wires. You are welcome to probe around with the voltmeter, to verify this. The ammeter measures current “going through” a wire, terminal or component. You are welcome to verify this by moving the ammeter to various positions in the circuit.