Basic Linear Circuits Review - Revision history

Lynch: /* Common Measurements and Units */

2009-12-19T17:53:54Z

Common Measurements and Units

2009-12-19T17:53:16Z

Common Measurements and Units

2006-07-05T19:39:50Z

Capacitance (Farad)

2006-07-05T19:37:49Z

Inductance (Henry)

2006-07-05T19:27:00Z

Capacitance (Farad)

2006-07-05T19:25:09Z

Power (Watt)

2006-07-05T19:23:21Z

Current (Ampere)

2006-06-26T22:55:32Z

Mechanical Analogs for Resistors, Capacitors, and Inductors

2006-06-26T22:53:21Z

Mechanical Analogs for Resistors, Capacitors, and Inductors

2006-06-26T22:52:59Z

Mechanical Analogs for Resistors, Capacitors, and Inductors

@@ Line 39: / Line 39: @@
 The unit of measurement for the resistance of a resistor is the ''ohm'', which is equal to 1 volt per amp.
-<math>1\Omega = \frac{1V}{1A}
+<math>1\Omega = \frac{1V}{1A}</math>
 ===Capacitance (Farad)===

@@ Line 35: / Line 35: @@
 <math>W=\frac{C}{s} \cdot \frac{J}{C}=\frac{J}{s}</math>
+===Resistance (Ohm)===
+The unit of measurement for the resistance of a resistor is the ''ohm'', which is equal to 1 volt per amp.
+<math>1\Omega = \frac{1V}{1A}
 ===Capacitance (Farad)===

@@ Line 37: / Line 37: @@
 ===Capacitance (Farad)===
-The unit of measurement for the capacitance of a capacitor is the ''farad'', which is equal to 1 coulomb per volt.  Most capacitors have capacitances much less than a farad, often measured in picofarads or microfarads.  A capacitor with a large capacitance stores a lot of electric charge without much voltage across it.
+The unit of measurement for the capacitance of a capacitor is the ''farad'', which is equal to 1 coulomb per volt.  The voltage across a capacitor is proportional to the amount of charge stored (i.e., the time-integral of current).  Most capacitors have capacitances much less than a farad, often measured in picofarads or microfarads.  A capacitor with a large capacitance stores a lot of electric charge without much voltage across it.
 <math>1F=\frac{1C}{1V}</math>

@@ Line 42: / Line 42: @@
 ===Inductance (Henry)===
-The unit of measurement for the inductance of an inductor is the ''henry'', which is equal to 1 volt-second per ampere.
+The unit of measurement for the inductance of an inductor is the ''henry'', which is equal to 1 volt-second per ampere.  The voltage across an inductor is proportional to the rate of change of current (measured in amps/second) through it.  The larger the inductance, the larger the voltage across the inductor for the same rate of change of current.  If current is flowing left to right through an inductor and increasing (respectively decreasing) with time, then the potential on the left side of the inductor is higher (respectively lower) than the potential on the right side.
 <math>1H=\frac{1V\cdot 1s}{1A}</math>

@@ Line 37: / Line 37: @@
 ===Capacitance (Farad)===
-The unit of measurement for the capacitance of a capacitor is the ''farad'', which is equal to 1 coulomb per volt.  Most capacitors have capacitances much less than a farad, often measured in picofarads or microfarads.
+The unit of measurement for the capacitance of a capacitor is the ''farad'', which is equal to 1 coulomb per volt.  Most capacitors have capacitances much less than a farad, often measured in picofarads or microfarads.  A capacitor with a large capacitance stores a lot of electric charge without much voltage across it.
 <math>1F=\frac{1C}{1V}</math>

@@ Line 28: / Line 28: @@
 ===Power (Watt)===
-The power absorbed or produced by a component is the rate at which it expends or generates energy.  The unit for power is the ''watt'', and 1 watt is equal to 1 joule per second.  Written in terms of voltage and current, the power is equal to the voltage across the component multiplied by the current through the component.  Thus, we get:
+The power absorbed or produced by a component is the rate at which it expends or generates energy.  The SI unit for power is the ''watt'', and 1 watt is equal to 1 joule per second.  Written in terms of voltage and current, the power is equal to the voltage across the component multiplied by the current through the component.  Thus, we get:
 <math>P=IV\,</math>

@@ Line 15: / Line 15: @@
 ===Current (Ampere)===
-An electric current represents electric charges flowing through a conductor.  By tradition, the current is modeled as a flow of positive charges, even though it was later discovered that current is in fact a flow of negative charges.  The ''ampere'', or ''amp'', is the unit for the current, and is determined by the rate of flow of the charges.  1 amp is equal to 1 coulomb per second.
+An electric current represents electric charges flowing through a conductor.  The ''ampere'', or ''amp'', is the unit for the current, and is determined by the rate of flow of the charges.  1 amp is equal to 1 coulomb per second.
 <math>1A=\frac{1C}{1s}</math>

@@ Line 81: / Line 81: @@
 |}
-In the table above, <mathv>v\,</math> is velocity for mechanical systems and voltage for electrical systems.  Force and voltage are ''effort'' variables.
+In the table above, <math>v</math> is velocity for mechanical systems and voltage for electrical systems.  Force and voltage are ''effort'' variables.
 Velocity and current are ''flow'' variables.