Introduction

Ohm’s law relates to the relationship that voltage and current from an ideal conductor develops. The relationship asserts that the potential difference or voltage that passes through a perfect conductor is relative to the current that passes through the conductor (Erjavec 2005). According to this law, the constant of proportionality is usually considered being resistance, which is denoted, R.

Therefore, Ohm’s law is as follows:

V=IR

Where V is considered to be the potential difference that exists between the two ends of an ideal conductor, R is the resistance towards current flow while I relate to the current that flows via the resistance.

Electric current is the rate of charge flow past a given point in an electric circuit, measured in Coulombs/second which is referred Amperes.

Voltage is the potential difference between two points within a conductor and is measured in volts.

Resistance is measured in ohms and refers to the resistance to flow of electric current.

Objects that obey Ohm’s law are usually regarded as ohmic or linear, which implies that the potential difference across the material that makes these objects varies in a linear manner with the current. Ohm’s law asserts that the total voltage present in a circuit is usually zero. This is practical when the circuit is closed and has at least one voltage source and at least one potential drop. An increase in the potential energy within a circuit makes charges to move from a lower potential to a higher potential (Lerner 1996). Electromotive force is a counteractive force that moves charges from a low potential to a high potential. Electromotive force is measured by using volts and is represented by E. Since energy is conserved; considerations are that the potential difference across the electromotive force should be equivalent to the potential difference across the rest of the circuit (Tyner, Knott & Mayer 1983). This implies that Ohm’s law is satisfied through the equation.

E= I R

E-electromotive force

I-current

R-resistance

Method

Materials and equipments needed

Ammeter

Resistance Box

Voltmeter

Rheostat

Unknown resistance

Power supply

Connecting wires

Switch

The circuit was turned on after careful inspection and the amount of current and voltage recorded as observed from the ammeter and voltmeter respectively. The procedure was repeated with varying voltage with the first unknown resistor. Then, the second unknown resistor was connected to the circuit and voltage varied to obtain readings that was filled in the observation table. Graphs of voltage against current were then plotted for each resistor using the experimental results from the observation table (Wilson & Hall 2009). The plotted points were then joined to obtain line of best fit.