Relating power to voltage and current.
Power is the speed of energy. It's the Joules per second. How does this compare to voltage and current, the two topics we focus on mostly in electric circuits?
Voltage is the energy per charge. Current is the charges per second. We can see if we multiply them together, we get joules per second, or power. This creates a new equation, P=IV
What's going on here? Remember that in a circuit, you don't know the number of charges that will flow, as this depends on how much you're using the circuit. What matters for whether the device will work or not is the energy each charge has, or the voltage.
But sometimes, we need to know how fast a device is using energy. A heater needs to put a certain number of joules/second into the air to heat a room. A power plant needs a certain joules per second to meet demand. This is where this equation is helpful.
A non electricity analogy is as follows: An ant colony needs a certain amount of sugar/second to grow its eggs.
How fast does it get its energy? Well, each ant can only carry a cetain amount of sugar. That's the voltage. How fast does it get its energy? It's the voltage times the number of ants per second. This last term is the current. So sugar per second = sugar per ant times ants per second. That's power.
Relating power to voltage and current.
Power is the speed of energy. It's the Joules per second. How does this compare to voltage and current, the two topics we focus on mostly in electric circuits?
Voltage is the energy per charge. Current is the charges per second. We can see if we multiply them together, we get joules per second, or power. This creates a new equation, P=IV
What's going on here? Remember that in a circuit, you don't know the number of charges that will flow, as this depends on how much you're using the circuit. What matters for whether the device will work or not is the energy each charge has, or the voltage.
But sometimes, we need to know how fast a device is using energy. A heater needs to put a certain number of joules/second into the air to heat a room. A power plant needs a certain joules per second to meet demand. This is where this equation is helpful.
A non electricity analogy is as follows: An ant colony needs a certain amount of sugar/second to grow its eggs.
How fast does it get its energy? Well, each ant can only carry a cetain amount of sugar. That's the voltage. How fast does it get its energy? It's the voltage times the number of ants per second. This last term is the current. So sugar per second = sugar per ant times ants per second. That's power.