## Circuit Lab B/C

Cathy-TJ
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### Re: Circuit Lab B/C

Calculate the resistance between terminals A and B in the infinite chain of resistors where all resistors are 1 ohm.
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mjcox2000
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### Re: Circuit Lab B/C

Positive and negative charge carriers behave the same in almost all circuits. However, there are some circuits in which it actually makes a difference whether charge carriers are positive or negative. What is an example of a circuit in which this matters, and why does the distinction matter for this circuit?
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Cathy-TJ
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Joined: January 20th, 2019, 7:13 pm
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State: VA

### Re: Circuit Lab B/C

Positive and negative charge carriers behave the same in almost all circuits. However, there are some circuits in which it actually makes a difference whether charge carriers are positive or negative. What is an example of a circuit in which this matters, and why does the distinction matter for this circuit?
A guess
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mjcox2000
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Joined: May 9th, 2014, 3:34 am
State: VA

### Re: Circuit Lab B/C

Positive and negative charge carriers behave the same in almost all circuits. However, there are some circuits in which it actually makes a difference whether charge carriers are positive or negative. What is an example of a circuit in which this matters, and why does the distinction matter for this circuit?
A guess
That’s not what I was going for.

Let me try rephrasing the question: Describe a circuit in which macro-level measurements of the circuit would differ depending on whether charge carriers are electrons flowing opposite conventional current or positive charge carriers flowing in the direction of conventional current.
MIT ‘23
TJHSST ‘19
Longfellow MS
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Cathy-TJ
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Posts: 28
Joined: January 20th, 2019, 7:13 pm
Division: C
State: VA

### Re: Circuit Lab B/C

Positive and negative charge carriers behave the same in almost all circuits. However, there are some circuits in which it actually makes a difference whether charge carriers are positive or negative. What is an example of a circuit in which this matters, and why does the distinction matter for this circuit?
A guess
That’s not what I was going for.

Let me try rephrasing the question: Describe a circuit in which macro-level measurements of the circuit would differ depending on whether charge carriers are electrons flowing opposite conventional current or positive charge carriers flowing in the direction of conventional current.
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mjcox2000
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Posts: 120
Joined: May 9th, 2014, 3:34 am
State: VA

### Re: Circuit Lab B/C

A guess
That’s not what I was going for.

Let me try rephrasing the question: Describe a circuit in which macro-level measurements of the circuit would differ depending on whether charge carriers are electrons flowing opposite conventional current or positive charge carriers flowing in the direction of conventional current.
MIT ‘23
TJHSST ‘19
Longfellow MS
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Cathy-TJ
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Joined: January 20th, 2019, 7:13 pm
Division: C
State: VA

### Re: Circuit Lab B/C

When and why would you use a Kelvin Double Bridge?
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Things2do
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### Re: Circuit Lab B/C

To measure unknown resistors under 1 Ohm?
John 5:46-47
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Cathy-TJ
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Posts: 28
Joined: January 20th, 2019, 7:13 pm
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State: VA

### Re: Circuit Lab B/C

To measure unknown resistors under 1 Ohm?
That's right!
This is because
You have the next question!
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mjcox2000
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Joined: May 9th, 2014, 3:34 am
State: VA

### Re: Circuit Lab B/C

Since no one has posted a question yet:

An LED with voltage drop $3.2V$ and internal resistance $2\Omega$ is in series with a voltage $V$ and resistance $R$. The LED’s maximum rated current is $10mA$, and the minimum current at which its light is visible is $100\mu A$.

1. What is the minimum series voltage $V$ for the LED to emit visible light?
2. Given the value of $V$, write equations for the minimum and maximum value of $R$ for the LED to emit visible light without burning out.
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Cathy-TJ
Member
Posts: 28
Joined: January 20th, 2019, 7:13 pm
Division: C
State: VA

### Re: Circuit Lab B/C

Since no one has posted a question yet:

An LED with voltage drop $3.2V$ and internal resistance $2\Omega$ is in series with a voltage $V$ and resistance $R$. The LED’s maximum rated current is $10mA$, and the minimum current at which its light is visible is $100\mu A$.

1. What is the minimum series voltage $V$ for the LED to emit visible light?
2. Given the value of $V$, write equations for the minimum and maximum value of $R$ for the LED to emit visible light without burning out.
Nationals Placings:
2019 Circuit Lab - 1
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2015 Picture This - 6

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mjcox2000
Member
Posts: 120
Joined: May 9th, 2014, 3:34 am
State: VA

### Re: Circuit Lab B/C

Since no one has posted a question yet:

An LED with voltage drop $3.2V$ and internal resistance $2\Omega$ is in series with a voltage $V$ and resistance $R$. The LED’s maximum rated current is $10mA$, and the minimum current at which its light is visible is $100\mu A$.

1. What is the minimum series voltage $V$ for the LED to emit visible light?
2. Given the value of $V$, write equations for the minimum and maximum value of $R$ for the LED to emit visible light without burning out.
MIT ‘23
TJHSST ‘19
Longfellow MS
Nationals medals

Cathy-TJ
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Posts: 28
Joined: January 20th, 2019, 7:13 pm
Division: C
State: VA

### Re: Circuit Lab B/C

What are the values of R3 and R4 if you want the battery to supply 83.3 mA to the circuit while the ammeter reads 0.00mA?

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mjcox2000
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Posts: 120
Joined: May 9th, 2014, 3:34 am
State: VA

### Re: Circuit Lab B/C

What are the values of R3 and R4 if you want the battery to supply 83.3 mA to the circuit while the ammeter reads 0.00mA?

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TJHSST ‘19
Longfellow MS
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Cathy-TJ
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Posts: 28
Joined: January 20th, 2019, 7:13 pm
Division: C
State: VA

### Re: Circuit Lab B/C

What are the values of R3 and R4 if you want the battery to supply 83.3 mA to the circuit while the ammeter reads 0.00mA?

You're correct!
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