# Relationship between Current, Voltage and Resistance

## Relationship between Current, Voltage and Resistance

• Current, voltage and resistance are interconnected as stated by Ohm’s law.
• Ohm’s law is applied to circuits with a constant temperature and is described by the equation V=IR. The voltage (V) across a component equals the current (I) through that component times its resistance (R).
• Voltage (V) is the energy transferred per unit of charge passed and is measured in Volts (V).
• Current (I) is the flow of electric charge and is measured in Amperes or Amps (A).
• Resistance (R) is a measure of the opposition to the passage of current and is measured in Ohms (Ω).
• In a parallel circuit, the total resistance decreases as more components are added. However, in a series circuit, the total resistance increases as more components are added.
• Components in a circuit contribute their own resistance, which is dependent upon factors such as the length of the conductor, the cross-sectional area, and the nature of the material.
• For resistors in series, the total resistance (R_total) is the sum of the individual resistances: R1 + R2 + R3…
• For resistors in parallel, 1/R_total = 1/R1 + 1/R2 + 1/R3…
• A higher resistance results in a lower current for a given voltage, according to Ohm’s Law. Conversely, a lower resistance results in a higher current.
• A greater potential difference (voltage) results in a greater current for a given resistance, also as per Ohm’s Law.
• For a fixed voltage, the higher the resistance of the component, the lower the current that flows through it.
• The current in a series circuit is the same everywhere, yet the voltage splits.
• On the other hand, in a parallel circuit, while the current splits, the voltage remains the same across all components.
• If the voltage is doubled, the current is also doubled given the resistance stays the same.
• Likewise, if the resistance is doubled, the current is halved assuming the voltage stays the same.
• The relationship between current, voltage and resistance is linear for most conductors, meaning that if you graph current versus voltage, you’ll get a straight line.
• Non-Ohmic conductors, like diodes or thermistors, do not exhibit this linearity, and their current-voltage graph is not a straight line.