I think...P=V^2/Rbut I m nt confirm..as I hv started this chap ...just yesterday

**The Relationship between Resistance (R), Power (P), and Constant Voltage (V) in a Filament Bulb**

The relationship between resistance (R), power (P), and constant voltage (V) in a filament bulb can be explained using Ohm's law and the power formula. Ohm's law states that the current flowing through a conductor is directly proportional to the voltage applied across it and inversely proportional to its resistance. The power formula states that the power dissipated in a circuit element is given by the product of the current flowing through it and the voltage applied across it.

**Ohm's Law:**

Ohm's law can be expressed mathematically as:
V = I * R

Where:
V is the voltage applied across the filament bulb,
I is the current flowing through the filament bulb, and
R is the resistance of the filament bulb.

From Ohm's law, we can derive the following relationship:
I = V / R

**Power Formula:**

The power dissipated in a circuit element can be calculated using the power formula:
P = I * V

Where:
P is the power dissipated in the filament bulb,
I is the current flowing through the filament bulb, and
V is the voltage applied across the filament bulb.

**Relationship between Resistance, Power, and Voltage:**

By substituting the value of current (I) from Ohm's law into the power formula, we can establish a relationship between resistance, power, and voltage:

P = (V / R) * V

Simplifying the equation further, we get:
P = V^2 / R

This equation shows that the power dissipated in a filament bulb is directly proportional to the square of the applied voltage and inversely proportional to the resistance of the bulb.

**Explanation:**

When a constant voltage (V) is applied across a filament bulb, the power dissipated in the bulb depends on the resistance of the filament. The resistance determines how much current will flow through the bulb. As the resistance increases, the current decreases, resulting in lower power dissipation. Conversely, a lower resistance allows more current to flow, resulting in higher power dissipation.

The relationship between resistance, power, and voltage can be understood as follows:

- If the resistance of the filament bulb remains constant, increasing the voltage will result in higher power dissipation. This is because the increased voltage will cause more current to flow through the bulb, leading to more power being dissipated as heat and light.

- On the other hand, if the voltage remains constant, increasing the resistance of the filament bulb will result in lower power dissipation. This is because the increased resistance will limit the current flowing through the bulb, reducing the power dissipated as heat and light.

Therefore, the resistance of the filament bulb plays a crucial role in determining the power dissipated for a given constant voltage.