Resistance Equals

The power p in watts w is equal to the voltage v in volts v times the current i in amps a.

Resistance equals. Using algebra techniques we can manipulate this equation into two variations solving for i and for r respectively. Ohm expressed his discovery in the form of a simple equation describing how voltage current and resistance interrelate. The resistance r in ohms ω is equal to the voltage v in volts v divided by the current i in amps a. V v i a r ω.

Also in the case of r 1 being equal to the value of r 2 that is r 1 r 2 the total resistance of the network will be exactly half the value of one of the resistors r 2. This brings us back to georg ohm. The same current passes through each resistor so each resistor does its job as you would expect. Electrical resistivity also called specific electrical resistance or volume resistivity and its inverse electrical conductivity is a fundamental property of a material that quantifies how strongly it resists or conducts electric current a low resistivity indicates a material that readily allows electric current.

Current is equal to the voltage divided by the. We can extend the water analogy to understand resistance too. For example a series circuit has a 2 ω ohm resistor a 5 ω resistor and a 7 ω resistor. Introducing the constant of proportionality the resistance one arrives at the usual mathematical equation that describes this relationship.

The voltage v in volts v is equal to the current i in amps a times the resistance r in ohms ω. The circuit with the higher resistance will allow less charge to flow meaning the circuit with higher resistance has less current flowing through it. G 1 r 2 where. Likewise if three or more resistors each with the same value are connected in parallel then the equivalent resistance will be equal to r n where r is the value of the resistor and n is the number of individual.

If we increase the voltage the current will increase. The voltage is equivalent to the water pressure the current is equivalent to the flow rate and the resistance is like the pipe size. If we increase the resistance the current will reduce. Since the current is set by the values of the voltage and resistance the ohm s law formula can show that.

Resistivity is commonly represented by the greek letter ρ. In this algebraic expression voltage e is equal to current i multiplied by resistance r. Ohm s law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Where i is the current through the conductor in units of amperes v is the voltage measured across the conductor in.

R resistance ohm ω u electrical potential volts i current flow ampere the reciprocal of resistance is conductance. G 1 10 ω 0 1 siemens s. The total resistance of the circuit is 2 5 7 14 ω. A basic electrical engineering equation called ohm s law spells out how the three terms relate.

G conductance siemens s example conductance.