What is Current? Understanding the Flow of Electricity

If voltage is the "push," then current is what actually moves. Electric current is the flow of electrons through a conductor, and it's one of the most fundamental concepts in electricity.

Back to Our Water Analogy

Remember our water pipe comparison?

• Voltage = Water pressure (the push)
• Current = Water flow (how much water moves through the pipe)
• Wires = Pipes

When you turn on a faucet, water flows out. The amount of water flowing per second is like electric current — it tells us how much electricity is moving through a wire.

What is Electric Current?

Electric current is the rate of flow of electric charge through a conductor. More specifically:

Current measures how many electrons pass through a point in a circuit every second.

The unit of current is the ampere (or "amp"), abbreviated as A. It's named after André-Marie Ampère, a French physicist who studied electromagnetism.

Understanding Amperes

One ampere means that about 6.24 billion billion electrons (6.24 × 10¹⁸) pass through a point every second! That's an incredibly large number, which is why we use amperes instead of counting individual electrons.

Types of Current

There are two types of electric current:

1. Direct Current (DC)

• Electrons flow in one direction
• Used in: batteries, phones, laptops, cars
• Symbol: ⎓

2. Alternating Current (AC)

• Electrons change direction back and forth
• Used in: wall outlets, power grids, home appliances
• Symbol: ∿

Most household electronics use DC power, but they get it from AC outlets through adapters that convert AC to DC.

Current in Everyday Life

The Danger of Current

Here's something important: current is what can hurt you, not voltage alone.

• Less than 1 mA: You can't feel it
• 1-5 mA: Slight tingle
• 10-20 mA: Painful, can't let go
• 100-300 mA: Can be fatal

This is why electrical safety is so important!

How Current Relates to Voltage

Current and voltage work together:

• Voltage provides the push
• Current is what flows because of that push
• Resistance (which we'll cover next) limits the flow

Think of it like this: voltage is like tilting a slide, current is the number of kids sliding down, and resistance is how rough the slide surface is.

A Simple Demonstration

You can observe current's effects:

1. Connect a battery to a small DC motor
2. The motor spins because current flows through it
3. Try a higher voltage battery (safely!) — more current flows, motor spins faster

Key Takeaways

• Current is the flow of electrons through a circuit
• It's measured in amperes (A)
• There are two types: DC (one direction) and AC (alternating)
• Current is what makes devices work — and what makes electricity dangerous
• Current depends on both voltage and resistance

What's Next?

You've learned about voltage (the push) and current (the flow). Now it's time to discover resistance — the force that opposes current flow. Check out: "What is Resistance? The Friction in Electrical Circuits."

Safety reminder: Never experiment with household electricity. Stick to low-voltage batteries when learning about circuits.