how many volt can runing in a 5meter wire the wire is made up of copper what is the reading of volt meater when a 100w bulb blowing 2min.

To determine the voltage running through a 5-meter copper wire when a 100-watt bulb is connected, we need to consider a few factors, including the resistance of the wire, the power of the bulb, and the voltage drop that occurs due to the wire's resistance. Let's break this down step by step.

Understanding the Basics

First, we need to know the relationship between power, voltage, and current. The formula for electrical power is:

P = V × I

Where:

• P is the power in watts (W)
• V is the voltage in volts (V)
• I is the current in amperes (A)

Calculating Current for the Bulb

For a 100-watt bulb, if we assume it operates at a standard voltage of 230 volts (common in many countries), we can rearrange the formula to find the current:

I = P / V

Substituting the values:

I = 100 W / 230 V ≈ 0.435 A

Resistance of the Copper Wire

The next step is to calculate the resistance of the 5-meter copper wire. The resistance (R) can be calculated using the formula:

R = ρ × (L / A)

Where:

• ρ is the resistivity of copper (approximately 1.68 × 10^-8 ohm-meters)
• L is the length of the wire in meters
• A is the cross-sectional area of the wire in square meters

For example, if we assume a standard wire gauge (like 1.5 mm²), the area A would be:

A = π × (d/2)²

Where d is the diameter of the wire. For 1.5 mm diameter, A ≈ 1.767 × 10^-6 m².

Now, substituting the values:

R = 1.68 × 10^-8 ohm-m × (5 m / 1.767 × 10^-6 m²) ≈ 0.0475 ohms

Voltage Drop Across the Wire

Now that we have the resistance, we can calculate the voltage drop (V_drop) across the wire using Ohm's Law:

V_drop = I × R

Substituting the current and resistance:

V_drop = 0.435 A × 0.0475 ohms ≈ 0.0207 V

Final Voltage Reading

The voltage at the bulb can be calculated by subtracting the voltage drop from the source voltage:

V_bulb = V_source - V_drop

If we assume the source voltage is 230 V:

V_bulb = 230 V - 0.0207 V ≈ 229.9793 V

Conclusion

In summary, when a 100-watt bulb is connected to a 5-meter copper wire, the voltage reading at the bulb after 2 minutes of operation would be approximately 229.98 volts, considering minimal voltage drop due to the wire's resistance. This example illustrates how electrical properties interact in a circuit, providing insight into practical applications of physics in everyday life.