Common Electrical Devices Used in Physics
Experiment #7
"Electric Devices and Meters"
Physics PHA202 PT2E
Santos, Nickerson Jeff F. February 27, 2002
0001864
Experiment No. 7
Electric Devices And Meters
OBJECTIVE:
To familiarize the students with the different types of electric devices and meters.
FOREWORD:
In order to perform experiments dealing with electric circuits, you must become familiar first with the devices and meters needed for such experiment. Some of the most common devices and meters to be used is described below.
1) RESISTORS Resistors are devices used to give a desired value of resistance. They are inserted into a circuit in order to lower the current of to produce a desired voltage drop. There are two kinds of resistors: a) the Fix Resistor and, b) the Variable Resistor. The fix resistor has a specific value of resistance which cannot be changed, while the variable resistor may have a any value of resistance within a specified range. Resistors have two important characteristics: a) its resistance in Ohms and, b) its wattage rating. Resistors are available in a wide variety of resistance values ranging from less than 1 ohm to mega ohms (MΩ). The power rating may be as high as 100 watts or may be lower than 1 watt. High-wattage resistors are usually of the wire wound type while low-wattage resistors are the carbon-composition type. The latter type is the one that we ordinarily see in which the resistance value is indicated by color codes. It is a fix resistor. For the variable resistor, it may be the plug type, the dial type or the switch type.
2) POTENTIOMETER This is a variable resistor with three terminals.
The two end terminals gives its fix maximum resistance while the middle terminal and an end terminal makes it a variable resistor.
3) RHEOSTAT This is a two terminal variable resistor that is used to vary the current in the circuit. Generally, rheostats are high-wattage wire wound resistors.
4) SWITCHES Switches are
"Electric Devices and Meters"
Physics PHA202 PT2E
Santos, Nickerson Jeff F. February 27, 2002
0001864
Experiment No. 7
Electric Devices And Meters
OBJECTIVE:
To familiarize the students with the different types of electric devices and meters.
FOREWORD:
In order to perform experiments dealing with electric circuits, you must become familiar first with the devices and meters needed for such experiment. Some of the most common devices and meters to be used is described below.
1) RESISTORS Resistors are devices used to give a desired value of resistance. They are inserted into a circuit in order to lower the current of to produce a desired voltage drop. There are two kinds of resistors: a) the Fix Resistor and, b) the Variable Resistor. The fix resistor has a specific value of resistance which cannot be changed, while the variable resistor may have a any value of resistance within a specified range. Resistors have two important characteristics: a) its resistance in Ohms and, b) its wattage rating. Resistors are available in a wide variety of resistance values ranging from less than 1 ohm to mega ohms (MΩ). The power rating may be as high as 100 watts or may be lower than 1 watt. High-wattage resistors are usually of the wire wound type while low-wattage resistors are the carbon-composition type. The latter type is the one that we ordinarily see in which the resistance value is indicated by color codes. It is a fix resistor. For the variable resistor, it may be the plug type, the dial type or the switch type.
2) POTENTIOMETER This is a variable resistor with three terminals.
The two end terminals gives its fix maximum resistance while the middle terminal and an end terminal makes it a variable resistor.
3) RHEOSTAT This is a two terminal variable resistor that is used to vary the current in the circuit. Generally, rheostats are high-wattage wire wound resistors.
4) SWITCHES Switches are