Laboratory Assignment
Ohm’s Law
Problem Statement: What is the relationship between current and voltage?
Introduction:
The theory of Ohm’s Law says that there is a direct relationship between current, I and voltage,
V; V = IR, where V = voltage, I = current, and R = resistance. Voltage is related to potential
energy and is measured in Volts. Current is the flow of charge and in measured in Amperes.
Resistance is the result of proportionality between voltage and current. It is the same value at
constant temperature. By knowing any two values of voltage, current, or resistance, the third one
can be calculated.
Experimental Method and Procedure:
For the experiment, a circuit was diagramed to measure the resistance of a fixed resistor R with a
voltmeter and ammeter. The ammeter was connected in series with the resistor so that the current
flowing through the resistor could be sensed, while the voltmeter was connected in parallel with
the resistor so that voltage across the resistor could be sensed. A DC power supply was used for
the voltage source. A switch was included and was connected immediately to the power supply
to control the current flow (if it went through or not based on the switch’s on and off position). A
device called a rheostat was also connected in series with the resistor and ammeter. It had three
points indicated A, B, and C. Points A and B were the endpoints. Point C was a sliding
component that could change the resistance between 0 and the maximum value. For this
experiment, point C was slid so that the maximum resistance was present because of safety
Ohm’s Law
Problem Statement: What is the relationship between current and voltage?
Introduction:
The theory of Ohm’s Law says that there is a direct relationship between current, I and voltage,
V; V = IR, where V = voltage, I = current, and R = resistance. Voltage is related to potential
energy and is measured in Volts. Current is the flow of charge and in measured in Amperes.
Resistance is the result of proportionality between voltage and current. It is the same value at
constant temperature. By knowing any two values of voltage, current, or resistance, the third one
can be calculated.
Experimental Method and Procedure:
For the experiment, a circuit was diagramed to measure the resistance of a fixed resistor R with a
voltmeter and ammeter. The ammeter was connected in series with the resistor so that the current
flowing through the resistor could be sensed, while the voltmeter was connected in parallel with
the resistor so that voltage across the resistor could be sensed. A DC power supply was used for
the voltage source. A switch was included and was connected immediately to the power supply
to control the current flow (if it went through or not based on the switch’s on and off position). A
device called a rheostat was also connected in series with the resistor and ammeter. It had three
points indicated A, B, and C. Points A and B were the endpoints. Point C was a sliding
component that could change the resistance between 0 and the maximum value. For this
experiment, point C was slid so that the maximum resistance was present because of safety
