Electrical Resistance

JMJ MARIST BROTHERS NOTRE DAME OF DADIANGAS UNIVERSITY MARIST AVENUE, GENERAL SANTOS CITY MULTITESTER instrumentality and Control CpE 511 NAME KURT RUSSEL C. CHUASeptember 01, 2012 CYNTHIA C. GONZAGADate of Submission teacher ENGR. JAY S. VILLAN, MEP-EE Introduction A multitester or mul cartridge clipter is a device which net be utilize to gather data about galvanising circuits. A basic multitester can measure metro, emf, and continuity while more advanced versions may be able to pr mangleer additional data.This tool can be very useful to throw away roughly the house, and any(prenominal)one who plans on doing electrical repairs should most unquestionably use a multitester for safety reasons. Multitesters can be use with the live off or on in most cases, although use the device with the electric flowing on can sometimes result in damage to the device. Theory Ammeters be apply for measuring current in a circuit and connected in series with the circuit. As ammeter is connected in series, the electromotive force drop crosswise ammeter terminals should be as low as possible.This requires that the opposite of the ammeter should be as low as possible. The current coil of ammeter has low current carrying electrical capacity whereas the current to be measured may be quite high. For this reason a low resistance is connected in parallel to the current coil. Voltmeters are employ to measure the potential difference crosswise any two points of the circuit these are connected in the parallel to the circuit. The resistance of voltmeter is kept very high by connecting a high resistance in series of the voltmeter with the current coil of the instrument.The effective voltage drop across the current coil of the voltmeter is only a atom of the total voltage applied across the voltmeter which is to be measured. An ohmmeter is a measuring instrument used to measure the resistance located between its leads. The resistance reading is indicated by a mech anical meter sweat which plights on electric current. The ohmmeter must hence have an internal source of voltage to create the necessary current to operate the movement, and also have appropriate ranging resistors to drop out just the right amount of current finished the movement at any given resistance.One major problem with this number is its reliance upon a stable barrage voltage for accurate resistance reading. If the battery voltage decreases, the ohmmeter scale will nod off accuracy. Conclusion Aside from using devices such(prenominal) asmultitester, the resistance esteem of aresistor can be decided by its discolour coding. There are small differences between measured and color coded values of the resistances. These differences may be caused by some factors such as the multitester used in the experiment and some mistakes make by the experimenters.It is much easier to read the resistance value of a resistor through a digital multitester than by using an analog multi tester and by color coding. In addition, in using an analog multitester, you have to first consider the range of the resistance and make the zero-ohm adjustment in each and every reading. In that case, that is the only time youcan acquire the resistance value after aslight inconvenient process. Pictorial Calculation For Ammeter * 0. 25A R1=99mV0. 25A R1= 0. 96 ? * 25mA R2=99mV25mA-R1 R2= 3. 564 ? * 2. 5mA R3=99mV2. 5mA-R2-R1 R3= 35. 64 ? For DC Voltmeter * 2. 5V R1=2. 5V49. 5A-Rm R1= 48, 505. 05051 ? * 10V R2=10V49. 5A-Rm-R1 R2= 151,515. 1515 ? * 50V R3=50V49. 5A-Rm-R1-R2 R3= 808,080. 8081 ? For AC Voltmeter * 10V Im=49. 5A0. 637 Im= 77. 70800628A R1=1. 41410-1. 477. 70800628A-Rm R1=161,947. 0707 ? * 25V R2=1. 41425-1. 477. 70800628A-Rm R2= 434,891. 9192 ? * 250V R3=1. 414250-1. 477. 70800628A-Rm R3= 4,529,064. 646 ?