Voltage Drop Across Indicator Lamp

In summary: UMMARY: In summary, Lisa is seeking help with a question about an electrical circuit involving six cells connected in series, an indicator lamp, and 600ft of AWG 18-gauge wire. She is unsure of the formulas needed to calculate the total voltage and amperage supplied by the battery, the total resistance of the wire, the voltage drop across the wire, and the voltage drop across the indicator lamp. An expert suggests using Ohm's Law to calculate these values.
  • #1
Lhawx
4
0
Hi,
I am new here so please bare with me. I know a bit about electrical and Electronics but I do not recall the formula for this application...it is a long question..please help! Here it is.

Six cells are connected in series to form a battery. Each cell has a rating of 1.5 volts and 1 amp. AWG 18-gauge wire joins the positive terminal of the battery formed by the series of cells to an indicator lamp 300ft away. Another 300ft length of AWG 18 wire runs from the lamp back to the battery's negative pole. The lamp acts as a 50 ohm resistor.

a. What are the total voltage and amperage supplied by the battery?
answer: 1.5 + 1.5 +1.5 + 1.5 + 1.5 + 1.5 = 9 volts. Since the cells are connected in series, the amps would remain the same at 1 amp.


b. What is the total resistance resulting from the 600ft of AWG 18 wire?
answer: 6.5100 ohms x .6 = 30.906 ohms


c. What is the voltage drop across the total length of wire?
answer: I do not remember hoe to calculate!


d. What is the voltage drop across the indicator lamp?
answer: I do not know how to calculate this!



I knop this is long but could someone please check this for me?

Thanks
Lisa:confused:
 
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  • #2
Hi Lisa,

a. If the cells are connected in Series Aiding, then 9 volts is correct (your problem doesn't indicate whether they are aiding or opposing so it is probably ok to assume aiding). The 1 amp is the rating of the batteries, not necessarily how much current they are outputting. The load on them will determine how much current is flowing.

b. The typical resistance per foot of 18 AWG is typically around 0.00751 for copper. So 0.00751 x 600 = 4.51 Ohms. Were you given another value for the per foot resistance of copper?

c. First you need to find the total current flowing in the circuit with Ohm's Law and the total resistance in the circuit. I = V/R. Once you have the total current (9 volts / Req Ohms), you can rearrange Ohm's Law to find the voltage drop in the wire (V = IR) with R being the resistance found in part b above.

d. Same as part c except you are given the resistance for the lamp (i.e. 50 ohms).

CS
 
  • #3


Hello Lisa,

I would be happy to help you with your questions.

For part c, to calculate the voltage drop across the total length of wire, you can use Ohm's law, which states that voltage drop (V) is equal to current (I) multiplied by resistance (R). In this case, the current is 1 amp and the total resistance is 30.906 ohms, as calculated in part b. Therefore, the voltage drop across the total length of wire would be 30.906 volts.

For part d, to calculate the voltage drop across the indicator lamp, you can use the same formula as in part c. The only difference is that the resistance will now be 50 ohms, as stated in the question. Therefore, the voltage drop across the indicator lamp would be 50 volts.

I hope this helps you with your calculations. Let me know if you have any further questions. Good luck!
 

What is voltage drop?

Voltage drop is the decrease in voltage that occurs when electricity flows through a conductor, such as a wire or circuit. It is measured in volts and is caused by resistance within the conductor.

What is an indicator lamp?

An indicator lamp, also known as a pilot light or indicator light, is a small light that is used to indicate the status or operation of a device or system. It is typically connected to a circuit and will turn on or off depending on the voltage passing through it.

Why is voltage drop across an indicator lamp important?

Voltage drop across an indicator lamp is important because it can affect the brightness of the lamp and its ability to accurately indicate the status of a system. It can also impact the overall performance and efficiency of the circuit.

What factors affect voltage drop across an indicator lamp?

The main factors that affect voltage drop across an indicator lamp are the voltage supplied to the circuit, the resistance of the conductor, and the type of indicator lamp being used. Other factors such as temperature and the length of the conductor can also have an impact.

How can voltage drop across an indicator lamp be reduced?

There are a few ways to reduce voltage drop across an indicator lamp, such as using a higher voltage supply, using a shorter or thicker conductor, or using a more efficient indicator lamp with lower resistance. Proper maintenance and regular checks of the circuit can also help identify and address any potential issues that may lead to excessive voltage drop.

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