Question

What is the principle of potential divider?

Answer 1

The principle of a potential divider is a basic concept in electrical circuits, and it's all about how a voltage is split or divided between two or more resistors connected in series.

Here's how it works:

1. Series Connection of Resistors

   When two resistors (R₁ and R₂) are connected in series to a voltage source (V), the total voltage from the source is divided between these resistors based on their resistances.

2. Voltage Division

   The voltage drop across each resistor depends on the ratio of its resistance compared to the total resistance. The larger the resistance, the larger the voltage drop across that resistor.

   The formula to calculate the voltage across a resistor in a potential divider is:
   \[
   V_{R1} = V \times \frac{R1}{R1 + R2}
   \]
   Where:
   - \( V \) is the total supply voltage.
   - \( R1 \) and \( R2 \) are the resistances of the two resistors.
   - \( V_{R1} \) is the voltage drop across resistor \( R1 \).

3. Example

   Let's say we have a 12V battery, with a 2Ω resistor (R₁) and a 4Ω resistor (R₂) connected in series:
   - Total resistance \( R_{\text{total}} = R₁ + R₂ = 2Ω + 4Ω = 6Ω \)
   - The voltage across \( R₁ \) will be:
     \[
     V_{R1} = 12V \times \frac{2Ω}{6Ω} = 4V
     \]
   - The voltage across \( R₂ \) will be:
     \[
     V_{R2} = 12V - V_{R1} = 12V - 4V = 8V
     \]

So, the voltage divides in the ratio of the resistances.

4. Applications

   - Adjusting voltage levels: You can use a potential divider to get a specific lower voltage from a higher voltage source.
   - Sensor circuits: For example, using a potentiometer (a variable resistor) as part of a potential divider to adjust voltage based on physical changes (like light intensity or temperature).

In essence, a potential divider allows us to create different voltage levels within a circuit based on the resistances we choose.