Electrical Circuits Lab: Measuring Current and Voltage, Lab Reports of Electrical and Electronics Engineering

Download Electrical Circuits Lab: Measuring Current and Voltage and more Lab Reports Electrical and Electronics Engineering in PDF only on Docsity! 1 Introduction: Solutions Prelab 1. If V=10V and R = 10kΩ, find I. I = V/R = 101/104 = 10-3 amps, = 1mA. 2. Should the DMM, set up to measure current, ever be placed in parallel with the DC power supply? Explain. In most cases never put the DMM current meter in parallel with a voltage source. An ideal voltage source will push a huge current and power into the ammeter and destroy the fuse. If the goal is to measure the short circuit current of a non-ideal voltage source, then you should make sure the fuse and ammeter can handle the expected current. Usually the ammeter is used to measure a current through a wire in a circuit. You must temporarily break open the wire and insert the meter in series with the two broken ends. Then the low resistance ammeter acts like a wire to the circuit but makes current measurements for you. 3. Given the circuit below, what would you expect VR1 to be with each of the following DC power supply settings? a) Vs = 5V, current limit = 10mA VR1 = 1k*10mA b) Vs = 5V, current limit = 2mA VR1 =1k*2mA Find VX. Vx = Vsrc*R2/(R2+R1) = 5 *(3 / 4) V. Laboratory ii. Use multimeter to measure power supply voltages. The power supply voltage will not be exactly calibrated to the same standard as the DMM. iii. Use multimeter to measure some resistors and pots. Resistors and pots have high tolerances. Their values are usually at least 1% off. Real parts do not meet perfection, but at least we get an idea how close is good enough. + _ VR1 + _ R1 = 1kΩVs + _ VX R1 = 1kΩ + _ R2 = 3kΩ5V