FEE Flashcards - Lecture 5 (1)
is an instrument used to measure current and must be connected in series with the circuit.
AMMETER
an instrument used to measure potential difference and must be connected in parallel with the part of the circuit whose potential difference is required.
VOLTMETER
an instrument for measuring resistance.
Ohmmeter
universal instrument, may be used to measure voltage, current and resistance.
MULTIMETER
may be used to observe waveforms and to measure voltages
OSCILLOSCOPE
an instrument for the measurement of power in an electrical circuit.
WATTMETER
may be used to measure both continuity and insulation
MEGGER
Produces energy in the form of voltage or current
ACTIVE CIRCUIT ELEMENTS
Stores energy in the form of voltage or current
PASSIVE CIRCUIT ELEMENTS
They do not have function to provide power gain
PASSIVE CIRCUIT ELEMENTS
They have function and provide power gain
ACTIVE CIRCUIT ELEMENTS
Examples of active circuit elements
DC generators, current, voltages, batteries
Examples of passive circuit elements
resistors, capacitors, inductors
characterized by terminal voltage and completely independent of the current through it.
Ideal Independent Voltage Source
the current through it is completely independent of the voltage across it.
Ideal Independent Current Source
in which the source quantity is determined by a voltage or current existing some other location in the electric system under examination.
Dependent/Controlled Source
Used to impede the flow of current.
Resistor
Types of ACTIVE CIRCUIT ELEMENTS
Independent and Dependent Source
TYPES OF RESISTORS
Fixed value Resistor and Variable Resistor
has a fixed amount of resistance in the circuit.
Fixed value Resistor
in this, the value of resistance is not fixed.
Variable Resistor
the amount (in percent) by which the actual ohmic resistance can be different from the color coded value.
Tolerance
Designed to store energy in its electric field and are often found in power supplies
CAPACITORS
ratio of the charge on one plate of a capacitor to the voltage difference between the two plates,
Capacitance
Unit of Capacitance
Farad (F)
Capacitance formula
C = Q/V (current/voltage)
Designed to store energy in its magnetic field. It consists of a coil conducting wire.
INDUCTORS
The property whereby an inductor exhibits opposition to the change of current flowing through it, measured in henrys (H)
Inductance
