What Happens to Current Through a Resistor in a Parallel Circuit When One is Removed?

What happens to the current through a specific resistor in a parallel circuit when another resistor is removed?

• A. It increases
• B. It decreases
• C. It remains the same
• D. It becomes zero

Answer: (C)

In a parallel circuit, each resistor is connected across the same two points and thus experiences the same voltage across it. The total current in the circuit is the sum of the currents through each parallel branch. When one resistor is removed from a parallel circuit, the overall resistance of the circuit increases, which typically leads to a reduction in total current supplied by the voltage source. However, the current flowing through the remaining resistors does not change as a direct result of removing one resistor. This is because the voltage across each remaining resistor remains constant, determined by the voltage of the source. Therefore, using Ohm's Law (V = IR), the current through each remaining resistor will stay the same. Consequently, when another resistor is removed from a parallel circuit, the current through the specific remaining resistor remains unchanged, as it continues to experience the same voltage while its resistance has not altered. Thus, the answer that asserts the current remains the same is indeed correct.

What Happens to Current Through a Resistor in a Parallel Circuit When One is Removed?

You know how in a parallel circuit, multiple resistors are connected across the same two points? It's like having several paths for the current to flow through. Each of these paths experiences the same voltage. So, when you remove one of those resistors, what really happens to the current through the remaining ones? Let’s break it down so it’s crystal clear.

Current Behavior in Parallel Circuits

Here’s the thing: when you yank a resistor from a parallel circuit—say goodbye to that resistor—the overall resistance of the circuit goes up. Sounds convoluted? Hang in there. This is primarily because the resistors in parallel provide multiple routes for the current to flow. Remove one, and that resistance increases, meaning less total current is supplied from the voltage source. So far, so good?

But wait! The real kicker is that the current flowing through the other resistors? Those currents don’t change. That’s right! They remain the same.

Constant Voltage Across Remaining Resistors

Let’s think about this in the context of Ohm's Law: V = IR. Here’s how it breaks down:

• V is the voltage—keeps on being the same no matter what happens to other resistors in the circuit.

• I is the current, which through any specific resistor can only change if its resistance or the voltage changes.

• R is the resistance of the remaining resistors that haven’t been tampered with.

Since the voltage remains constant (thanks to our reliable voltage source), and the resistance of these resistors hasn’t changed, the current through each one stays steady. It feels like a magic trick: you remove one resistor and what happens? The others remain unaffected.

Why This Concept Matters

Understanding this principle isn’t just a nerdy tidbit; it’s a crucial piece for those prepping for exams like the MCAT. You’ll often encounter questions that test your comprehension of circuit behavior. If you’ve spent time studying circuits for the MCAT, grasping how one resistor’s removal affects others can help you avoid unnecessary pitfalls.

A Quick Recap

So, let’s summarize:

• When you remove a resistor in a parallel circuit, the total resistance increases.

• The total current drawn from the voltage source decreases, but…

• The current through each remaining resistor stays the same because the voltage across them is unchanged.

In conclusion, answering questions on this topic, like our multiple choice question, should feel more straightforward now. The correct choice is that the current through that specific remaining resistor remains the same. Familiarize yourself with concepts like this, and you'll not only ace the questions but also have a solid grasp of electrical principles.

Understanding parallel circuits is fundamental, not just for tests, but for real-world applications like electrical engineering or even DIY home projects. Remember, knowledge is power, and mastering these concepts can empower you to tackle more complex circuit theories down the line!