Where is ELCB used?
2 Answers
Resistors themselves do not directly limit voltage; they limit current. However, they can indirectly affect voltage in a circuit through their influence on current. Here’s how:
1. **Ohm's Law**: According to Ohm’s Law, \( V = I \times R \), where \( V \) is voltage, \( I \) is current, and \( R \) is resistance. When you introduce a resistor into a circuit, it creates a voltage drop across itself based on the current flowing through it and its resistance value. So, while the resistor does not limit the voltage in a circuit directly, it does cause a voltage drop proportional to the current and resistance.
2. **Voltage Divider**: Resistors can be used in a voltage divider configuration to produce a lower voltage from a higher voltage source. In this setup, two or more resistors are connected in series, and the output voltage is taken from the junction between them. The output voltage is a fraction of the input voltage, determined by the values of the resistors. For instance, with resistors \( R1 \) and \( R2 \) in series, the output voltage \( V_{out} \) is given by:
\[
V_{out} = V_{in} \times \frac{R2}{R1 + R2}
\]
Here, \( V_{in} \) is the input voltage, and \( V_{out} \) is the reduced voltage.
3. **Current Limiting**: In circuits where a specific voltage needs to be maintained across a load, resistors are used to limit the current to a safe level. For example, in an LED circuit, a resistor is placed in series with the LED to limit the current flowing through it. While the resistor does not limit the voltage directly, it ensures that the current is kept within safe limits, which indirectly affects the voltage drop across the LED and resistor.
4. **Voltage Drop**: When resistors are used in a circuit, they cause a voltage drop. If you have a resistor in series with a load, the voltage drop across the resistor plus the voltage drop across the load will equal the source voltage (according to Kirchhoff’s Voltage Law).
In summary, while resistors do not limit voltage directly, they influence the voltage seen by components in a circuit by controlling the current and creating voltage drops according to Ohm's Law.
1. **Ohm's Law**: According to Ohm’s Law, \( V = I \times R \), where \( V \) is voltage, \( I \) is current, and \( R \) is resistance. When you introduce a resistor into a circuit, it creates a voltage drop across itself based on the current flowing through it and its resistance value. So, while the resistor does not limit the voltage in a circuit directly, it does cause a voltage drop proportional to the current and resistance.
2. **Voltage Divider**: Resistors can be used in a voltage divider configuration to produce a lower voltage from a higher voltage source. In this setup, two or more resistors are connected in series, and the output voltage is taken from the junction between them. The output voltage is a fraction of the input voltage, determined by the values of the resistors. For instance, with resistors \( R1 \) and \( R2 \) in series, the output voltage \( V_{out} \) is given by:
\[
V_{out} = V_{in} \times \frac{R2}{R1 + R2}
\]
Here, \( V_{in} \) is the input voltage, and \( V_{out} \) is the reduced voltage.
3. **Current Limiting**: In circuits where a specific voltage needs to be maintained across a load, resistors are used to limit the current to a safe level. For example, in an LED circuit, a resistor is placed in series with the LED to limit the current flowing through it. While the resistor does not limit the voltage directly, it ensures that the current is kept within safe limits, which indirectly affects the voltage drop across the LED and resistor.
4. **Voltage Drop**: When resistors are used in a circuit, they cause a voltage drop. If you have a resistor in series with a load, the voltage drop across the resistor plus the voltage drop across the load will equal the source voltage (according to Kirchhoff’s Voltage Law).
In summary, while resistors do not limit voltage directly, they influence the voltage seen by components in a circuit by controlling the current and creating voltage drops according to Ohm's Law.