# Need help for my question regarding circuit

In summary, the circuit is correct, but modifications may be needed in order to achieve the desired results. The equivalent voltage is 1.83 V when 20 mA is flowing through the LED. @20 mA indicates the expected voltage drop across the LED. S3 connects the positive of V2 to the negative of V2. Closing S3 would short out the circuit and cause the LED to blink.
Hello ,
I am having problem with one question.
In the figure below which resistors values and voltage source values are sufficient so that LED can work properly.
Is the circuit correct,do i need some modifications on that.
If it is correct what will be the equivalent voltage.
what does "@20 mA" means in this LED.

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Before going any further, what happens when you close S3?

I don't know nothing at all ... please guide me which you know of ... if i am wrong in this circuit please guide me

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Hello ,
I am having problem with one question.
In the figure below which resistors values and voltage source values are sufficient so that LED can work properly.
Is the circuit correct,do i need some modifications on that.
If it is correct what will be the equivalent voltage.
what does "@20 mA" means in this LED.

There may be problems with the circuit, but in order to help you find them we will need to know what the circuit should be doing. Is this your own design? If so, what are the design goals?

The "1.83 V @20 mA" type labels indicate the expected voltage drop across the LED when the specified current of 20 milliamps is flowing through it. Note that 20 mA is a typical operating current for many LEDs.

skeptic2 said:
Before going any further, what happens when you close S3?

I don't know nothing at all ... please guide me which you know of ... if i am wrong in this circuit please guide me

S3 connects the positive of V2 to the negative of V2. What happens if you short out a voltage source like that?

Ohms law... V=IR so I = V/R but R=0

Besides being shorted out when S3 is closed, what purpose is V2 supposed to accomplish?

As gneill says, we need to know what the circuit is supposed to do before we can help you. When will the switches be activated? Will they never be closed together or can it happen that all of them are closed at the same time? Are they supposed to light up together or one at a time? Why is there 2 voltages supplies?

I was told in assignment to make a circuit and monitor each light blinking ... this is why i made this circuit and want to monitor it with switches open and closed... The major thing which i need to know is that
1)With switch/switches closed which led/leds is going to blink
2)The direction of current will go from where to where
3)What should be the value of resistors,current in the circuit
4)Which voltage source will dominate and what will be the total voltage of the circuit
5)If there is any flaw in the circuit please let me know.I will change it.

I was told in assignment to make a circuit and monitor each light blinking ...
Hi mremadahmed. I'm afraid that your explanation is still not clear. I think you are wrongly using the words "monitor" and "blink". Can you write your explanation again, but this time avoid those two words and choose other equivalent words that mean the same to you.

Were you told that you must use two voltage sources? If not, why have you chosen two?

Can you include a .jpg of the assignment question and its accompanying diagram? Post it even if it is not in English.

## 1. How do I calculate the total resistance in a circuit?

In order to calculate the total resistance in a circuit, you will need to use Ohm's Law, which states that resistance (R) is equal to the voltage (V) divided by the current (I), or R = V/I. You will also need to use the concept of series and parallel resistors, depending on the type of circuit you are dealing with.

## 2. What is the difference between series and parallel circuits?

In a series circuit, the components are arranged in a single path, meaning that the current flowing through one component will also flow through the others. In a parallel circuit, the components are arranged in multiple paths, meaning that the current will split up and flow through each component separately.

## 3. How do I calculate the total current in a series circuit?

In a series circuit, the total current is equal to the sum of the individual currents through each component. This means that the total current is the same throughout the circuit, and can be calculated using Ohm's Law (I = V/R).

## 4. How do I determine the voltage across a specific resistor in a parallel circuit?

In a parallel circuit, the voltage across each resistor is the same, as it is determined by the voltage source. However, the current through each resistor may differ. To calculate the voltage across a specific resistor, you can use Ohm's Law (V = IR), where I is the current through that resistor.

## 5. How do I troubleshoot a circuit that is not functioning properly?

If a circuit is not functioning properly, the first step is to check for any loose connections or damaged components. You can also use a multimeter to measure the voltage and current at various points in the circuit to identify any potential issues. If necessary, you may need to consult a schematic or seek the help of a professional to diagnose and fix the problem.

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