**What does a variable resistor do?** Variable resistor

A resistor **limits the passage of electrical current**. A fixed resistor has a resistance that does not change. The resistance of this resistor is changed by moving the position of a slider. A variable resistor is used in some dimmer switches and volume controls.

**How does a variable resistor change the current?** A variable resistor can be used to control the current passing through a circuit. **If the potential difference is constant then the current decreases as the resistance of the variable resistor increases**. A variable resistor can be used to control the potential difference of another component in series with it.

**Can a variable resistor is used to control voltage?** **Variable resistors can be altered to control either the current or voltage of a circuit**. Common types include potentiometers that are operator controlled and thermistors that change resistance according to temperature.

**What happens to voltage when the resistance of the variable resistor is increased?** If the resistance of a resistor is 1 Ω Ω , the current would be 3.0 A. If the resistance increases to 2 Ω Ω , given the same value for the voltage, the current becomes 1.5 V. As observed, the relationship between current and resistance is inverse such that **current decreases as resistance increases**.

## What does a variable resistor do? – Additional Questions

### Does adding a resistor decrease voltage?

Voltage varies directly with current. “R” is the constant of proportionality telling how much it varies. **If I add in a resistor to a circuit, the voltage decreases**. If you have a resistor in a circuit, with a current flowing through it, there will be a voltage dropped across the resistor (as given by Ohm’s law).

### Does increasing resistance increase voltage?

It can be seen from the equation that if either the current or the resistance is increased in the circuit (while the other is unchanged), the voltage will also have to increase.

### How does resistance affect voltage?

The relationship between current, voltage and resistance is expressed by Ohm’s Law. This states that the current flowing in a circuit is directly proportional to the applied voltage and inversely proportional to the resistance of the circuit, provided the temperature remains constant.

### What happens to voltage when current increases?

According to Ohm’s Law, **Current Increases** when Voltage increases (I=V/R), but Current decreases when Voltage increases according to (P = VI) formula.

### What happens to the voltage and current of the fixed resistor as you increase the resistance of the variable resistor?

**The resistance of a variable resistor does not change with increase in voltage**. Hence, a fixed amount of electric current flows through the variable resistor. If we vary the resistance of the variable resistor, the amount of electric current flowing through a variable resistor increases or decreases.

### When resistance is increased What happens to the current?

As the resistance increases, **the current decreases**, provided all other factors are kept constant. Materials with low resistance, metals for example, are called electrical conductors and allow electricity to flow easily.

### How do you increase voltage?

Increasing AC Voltage is the same as increasing DC voltage. To increase the voltage, we **connect the AC voltages in series to get a higher output voltage**. If the frequency of all the voltages are the same, the magnitude of the voltages simply add. The voltages will just add, so the total voltage will be 28Vac at 60Hz.

### Is voltage directly proportional to resistance?

Ohm’s law states that the voltage or potential difference between two points is directly proportional to the current or electricity passing through the resistance, and **directly proportional to the resistance of the circuit**. The formula for Ohm’s law is V=IR.

### Why does voltage decrease when current increases?

So, holding the power constant, an increase in voltage results in a decrease in current. **Since the ohmic losses in a transmission line are proportional the square of the current, reducing the current by 50% cuts the power loss by 75%**.

### What causes low voltage in a circuit?

**Old wires and corrosion** are two of the common causes of low voltage. Another reason can be dirty connections and weak insulation. Apart from that, if the population increases the demand increases and this leaves an impact on the distribution of voltage.

### Does higher voltage mean more current?

In a linear circuit of fixed resistance, if we increase the voltage, the current goes up, and similarly, if we decrease the voltage, the current goes down. This means that **if the voltage is high the current is high**, and if the voltage is low the current is low.