Resistors in series | Circuits | Physics | Khan Academy

TL;DR

Current flows in a series circuit, and the voltage drops across each device are equal to the total voltage drop.

Transcript

Let's make our circle a little bit more complicated now. So let's say I have a battery again, and let me do it in a different color just for variety. That's the positive terminal, that's the negative terminal. Let's say I have this perfect conductor, and let's say I have one resistor and I have another resistor. I don't know, just for fun, let's th... Read More

Key Insights

• ❓ The current through a series circuit is constant.
• 💦 Voltage drops occur across each device in the circuit.
• ⚡ The voltage across the entire circuit is equal to the sum of the voltage drops across the devices.
• 🍹 The total resistance in a series circuit is equal to the sum of the individual resistances.
• 👮 The current can be calculated using Ohm's law: current equals voltage divided by total resistance.
• ❓ Series circuits are characterized by elements connected in a sequential manner without branching off.
• ⚡ The voltage across elements in the circuit remains constant.

Questions & Answers

Q: What is the direction of current flow in a series circuit?

In a series circuit, the convention is that current flows from the positive to the negative terminal.

Q: Why is the voltage constant between elements in the circuit?

The voltage is constant because the wires are assumed to be perfect conductors, and the resistance takes place in the resistors.

Q: How does the probability of electron collisions change when resistors are placed in series?

When resistors are in series, the probability of electrons bumping into things and creating resistance increases.

Q: What is the relationship between the total resistance and the individual resistances in a series circuit?

In a series circuit, the total resistance is equal to the sum of the individual resistances.

Summary & Key Takeaways

• In a series circuit, the current flows through each element in sequence without branching off.

• The voltage is constant across elements in the circuit.

• The total resistance in a series circuit is equal to the sum of the individual resistances.