Relationship between Current, Voltage and Resistance

Current, Voltage, and Resistance Relationships

Ohm’s Law

Ohm’s Law states that the current flowing through a conductor is directly proportional to the voltage across it, provided the temperature remains constant. It can be represented as the equation I = V/R, where I is current, V is voltage and R is resistance.
Current (I) is the flow of electrical charge and is measured in units of Ampere (A) using an ammeter.
Voltage (V) is the potential difference across a component and is measured in units of Volts (V) using a voltmeter.
Resistance (R) is a measure of opposition to the flow of current and is measured in units of Ohms (Ω) using an ohmmeter.

Electrical Resistance

The resistance of a component can be determined from the gradient of a current-voltage graph; a steeper gradient indicates a lower resistance.
Factors affecting resistance include the type of material, length, cross-sectional area and temperature of the conductor. When a component gets hot (like a filament lamp) its resistance increases, causing the current-voltage graph to curve.

Power (P) is equal to the product of current (I) and voltage (V), P=IV.
The amount of energy transferred by electrical work is given by the equation E = Pt, where E is energy, P is power and t is time.
Different electrical components, like resistors or diodes, have different I–V characteristics, meaning they influence current, voltage, and resistance in different ways.