You have a device that needs a voltage reference of 3.0 V, but you have only a 9.0 V battery. Fortunately, you also have several

Question

1 year ago

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You have a device that needs a voltage reference of 3.0 V, but you have only a 9.0 V battery. Fortunately, you also have several

10 k!1 resistors. Show how you can use the resistors and the battery to make a circuit that provides a potential difference of3.0 V.

Physics

2 answers:

Nimfa-mama [501] · Answer 1 · 2023-10-03T02:52:41+03:00

Answer:

Explanation:

Solution:

- We are to develop a circuit that has an input of available battery 9.0 V and has an output potential difference of 3.0 V

- We are given:

Battery ..... 9.0 V

Resistors ... 10 Kohms

- We will develop a potential divider circuit by placing a few resistors in series and then connecting in between resistors to get our desired voltage.

- How many resistors should we use ?

We know that if we add series resistance in a circuit the current decreases proportionally. However, the potential difference across resistors also changes.

- Our desired voltage is a ratio of input battery voltage.

Input / Output = 9 / 3 = 3

We can use this ratio as the number of "Identical resistors" that can be placed in series to give us the desired voltage. Note: This would not be true if we did not had any identical resistors.

- We will place 3, 10 Kohms resistors in series.

- To verify we will calculate the potential difference across each resistor. The current of the total circuit is:

I = V / R_eq

R_eq = 3*R = 30 kohms

I = 9 / 30,000 = 0.0003 Amps

- Now the potential difference for each resistor:

V = I*R_each

V = 0.0003*(10,000)

V = 3.0 V

- We can take two leads across any 10 kohms resistor and the potential difference across the leads would be the desired voltage 3.0 V.