So, what you mean is that the voltmeter measures with R2 for maximum voltage drop and for minimum, without R2, but for R3. In all cases, R2 is not considered as a variable resistor. Thank you for your precious reply.DaveE said:
Yes, thank you for your information.DaveE said:
A variable resistor, also known as a potentiometer or rheostat, is a resistor whose resistance can be adjusted manually. It works by varying the length of the resistive material through which the current flows, thereby changing the resistance and, consequently, the voltage and current in the circuit.
Changing the resistance in a circuit affects the voltage drop across the resistor according to Ohm's Law (V = IR). Increasing the resistance will increase the voltage drop across the resistor for a given current, while decreasing the resistance will reduce the voltage drop.
Yes, a variable resistor can be used to control the brightness of a light bulb. By adjusting the resistance, you can control the amount of current flowing through the bulb, which in turn controls its brightness. Increasing the resistance will dim the bulb, while decreasing the resistance will make it brighter.
A potentiometer is a three-terminal variable resistor used to adjust voltage in a circuit, typically used as a voltage divider. A rheostat is a two-terminal variable resistor used to control current. Both can be used to vary resistance, but their applications differ based on the number of terminals and the way they are connected in the circuit.
To calculate the voltage variation when using a variable resistor, you can use Ohm's Law and the voltage divider rule. Ohm's Law states that V = IR, where V is voltage, I is current, and R is resistance. The voltage divider rule helps determine the voltage drop across each resistor in a series circuit. By adjusting the variable resistor, you change the total resistance, which in turn changes the voltage drop across each component in the circuit.