# Ohms Law Investigation

Topics: Ohm's law, Resistor, Electric current Pages: 7 (1405 words) Published: August 25, 2013
Ohms Law
Ohms Law

Thomas More College

Thomas More College

How it applies to different materials
Lucas Cosmidis 11 physics

How it applies to different materials
Lucas Cosmidis 11 physics

Aim/Purpose
The aim is to investigate whether 12v light bulb and a ceramic resistor are either non- ohmic or ohmic. From results calculations can be made to find the resistance produced and then graphed indicating whether the light bulb and ceramic resistor is ohmic or non ohmic

Background Information

An electric circuit is formed when a conductive path is created to allow free electrons to continuously move. This continuous movement of free electrons through the conductors of a circuit is called a current, and it is often referred to in terms of "flow," just like the flow of a liquid through a hollow pipe.

The force motivating electrons to "flow" in a circuit is called voltage. Voltage is a specific measure of potential energy that is always relative between two points. When we speak of a certain amount of voltage being present in a circuit, we are referring to the measurement of how much potential energy exists to move electrons from one particular point in that circuit to another particular point. Without reference to two particular points, the term "voltage" has no meaning.

Free electrons tend to move through conductors with some degree of friction, or opposition to motion. This opposition to motion is more properly called resistance. The amount of current in a circuit depends on the amount of voltage available to motivate the electrons, and also the amount of resistance in the circuit to oppose electron flow. Just like voltage, resistance is a quantity relative between two points. For this reason, the quantities of voltage and resistance are often stated as being "between" or "across" two points in a circuit.

- All about Circuits. How voltage, current, and resistance relate In-text: (All about Circuits n.d.) Bibliography: All about Circuits. n.d.. How voltage, current, and resistance relate. [online] Available at: http://www.allaboutcircuits.com/vol_1/chpt_2/1.html [Accessed: 10 Jun 2013].

Ohms Law: Ohm’s law states that the amount of current I ﬂowing across a deviceis proportional to the voltage V that is applied across that device. Some devices such as resistors and wires obey Ohm’s Law. Mathematically, this can be written as V = IR Ohmic Devices: If a device follows ohm’s law for all voltages across it, the device is called an Ohmic device (In other words, the resistance of the device is independent of the magnitude and polarity of the applied potential diﬀerence), and the resistance is said to have a constant value (static resistance). In this case, the plot of V versus I is a straight line passing through the origin, as shown in Figure 1, and the slope of the line is the resistance R of the device. Non-ohmic Devices: If a device behaves in a way that is NOT described by Ohm’s law, (i.e. the resistance is not constant, but changes in a way that depends on the voltage across it.) The device is said to be non-Ohmic * Unknown. Ohmic and Non Ohmic Devices In-text: (Unknown n.d.)...

Bibliography: Concise Physics. n.p.. Ohmic and non-ohmic conductors. [online] Available at: http://physics.nayland.school.nz/VisualPhysics/NZ-physics%20HTML/14_Electronics/chapter14a.html [Accessed: 19 Jun 2013].