V=IR hence voltage across a series resistor circuit is proportional to the value of the resistance.

Introduction:
In a series resistor circuit, multiple resistors are connected in a sequential manner such that the current flows through each resistor in the same path. The voltage across a series resistor circuit refers to the potential difference measured across each resistor in the circuit.

Explanation:
The voltage across a series resistor circuit is directly proportional to the value of the resistance itself. This relationship can be explained using Ohm's Law, which states that the voltage across a resistor is equal to the product of the current flowing through it and its resistance.

Ohm's Law:
Ohm's Law can be expressed mathematically as V = I * R, where V is the voltage across the resistor, I is the current flowing through it, and R is the resistance.

Effect of Resistance on Voltage:
When the resistance in a series resistor circuit increases, the voltage across it also increases proportionally. This can be understood by rearranging Ohm's Law as V = I * R. As the resistance value (R) increases, for the same current (I), the voltage (V) across the resistor increases. Similarly, if the resistance value decreases, the voltage across the resistor decreases.

Example:
Consider a series resistor circuit with two resistors, R1 and R2, connected in series. Let's assume the voltage across R1 is V1 and the voltage across R2 is V2. According to Ohm's Law, V1 = I * R1 and V2 = I * R2. Since the same current flows through both resistors in a series circuit, we can rewrite these equations as V1 = I * R1 and V2 = I * R2.

From these equations, it is evident that the voltage across each resistor is directly proportional to its resistance value. If the resistance of R1 is doubled, the voltage across it will also double. Similarly, if the resistance of R2 is tripled, the voltage across it will also triple.

Conclusion:
In a series resistor circuit, the voltage across each resistor is directly proportional to the value of its resistance. This relationship is derived from Ohm's Law, which states that the voltage across a resistor is equal to the product of the current flowing through it and its resistance.

B