Why is there no voltage drop through this resistor?

In summary, the conversation discusses a wiring setup involving a 9V battery, a 1000 uF capacitor, a 660 Ohm resistor, and a green LED. The voltage drop across the capacitor is 6.5V and across the LED is 1.5V, but there is no voltage drop across the resistor. The conversation then suggests discharging the capacitor and removing it to observe changes in the circuit, and encourages further study of capacitors to better understand the circuit. The conversation also reminds everyone to be polite in future discussions.
  • #1
trickybilly
16
7
I have wired in series: + of 9V battery --- + of 1000 uF capacitor --- 660 Ohm resistor --- + of a green LED --- - of the 9V battery. Remark: the 9V battery is a bit depleted 7.8 V unconnected.

Voltage drop across the capactor is 6.5V, across the LED is 1.5V but 0V across the resistor. Why there is no voltage drop across the resistor?
 
Engineering news on Phys.org
  • #2
Try this:
1) discharge the capacitor by placing the resistor across it for several seconds.
2) connect everything back up except the LED to - of the battery
3) connect the - of the battery while carefully watching the LED.

What did you see?

4) now remove the capacitor

What do you see now?

BoB
 
  • #3
trickybilly said:
I have wired in series: + of 9V battery --- + of 1000 uF capacitor --- 660 Ohm resistor --- + of a green LED --- - of the 9V battery. Remark: the 9V battery is a bit depleted 7.8 V unconnected.

Voltage drop across the capactor is 6.5V, across the LED is 1.5V but 0V across the resistor. Why there is no voltage drop across the resistor?
Do you understand how capacitors work?

EDIT: Let me rephrase that: you clearly don't yet understand how capacitors work, so that's where you should focus. Study capacitors for a bit and you will understand what is happening in your circuit. That's where rbelli1 is leading you.
 
  • #4
@phinds I have received my answer. Do YOU understand it?

2r7y9so.jpg
 

Attachments

  • 2r7y9so.jpg
    2r7y9so.jpg
    35.1 KB · Views: 701
  • Like
Likes Tom.G
  • #5
trickybilly said:
Do YOU understand it?
You'll bite a helping hand ? Thanks for the warning.
 
  • Like
Likes sophiecentaur and phinds
  • #6
Since the OP has been answered we will close this thread. Everyone, please remember to be polite in future threads.
 
  • Like
Likes sophiecentaur and jim hardy

1. Why is there no voltage drop through this resistor?

Voltage drop occurs when there is a difference in potential between two points. In a resistor, there is a steady flow of current and a constant resistance, resulting in a uniform potential difference across the resistor. This means that there is no change in potential and therefore no voltage drop.

2. How does the resistance affect the voltage drop?

The resistance of a resistor determines the amount of current that can flow through it. A higher resistance means less current can flow, resulting in a smaller voltage drop. Similarly, a lower resistance allows more current to flow, resulting in a larger voltage drop.

3. Can other factors affect the voltage drop in a resistor?

Yes, other factors such as temperature and the material of the resistor can affect the voltage drop. As temperature increases, the resistance of a resistor also increases, leading to a smaller voltage drop. The material of the resistor can also affect its resistance and therefore the voltage drop.

4. Why is it important to measure voltage drop in a circuit?

Voltage drop is an important measurement in a circuit as it helps to determine the efficiency of the circuit. A large voltage drop may indicate a problem with the circuit, such as a high resistance or a faulty component. It can also help to identify the flow of current and the power consumption in the circuit.

5. How can I calculate the voltage drop in a resistor?

The voltage drop in a resistor can be calculated using Ohm's Law, which states that voltage (V) equals current (I) multiplied by resistance (R). So, V = I x R. This means that if you know the current and resistance of a resistor, you can calculate the voltage drop. Additionally, using a multimeter to measure the voltage across the resistor can also give an accurate reading of the voltage drop.

Similar threads

  • Electrical Engineering
Replies
3
Views
2K
Replies
4
Views
2K
  • Electrical Engineering
Replies
8
Views
2K
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
526
  • Introductory Physics Homework Help
Replies
2
Views
476
Replies
32
Views
9K
Replies
35
Views
4K
  • Electrical Engineering
2
Replies
47
Views
5K
  • Electrical Engineering
Replies
29
Views
3K
Back
Top