a tungsten and coil has a resistance of 12 ohm at 15 degree celsius is the temperature coefficient of resistance of tungsten is 0.004 calculate the equal resistance at 80 degree Celsius

The resistance of the tungsten coil at 80 degrees Celsius is 15.12 ohm

Explanation:

The given parameters are;

The resistance of the tungsten coil at 15 degrees Celsius = 12 ohm

The temperature coefficient of resistance of tungsten = 0.004/°C

The resistance of the tungsten coil at 80 degrees Celsius is found using the following relation;

R₂ = R₁·[1 + α·(t₂ - t₁)]

Where;

R₁ = The resistance at the initial  temperature = 12 ohm

R₂ = The resistance of tungsten at the final temperature

t₁ = The initial temperature = 15 degrees Celsius

t₂ = The final temperature = 80 degrees Celsius

α = temperature coefficient of resistance of tungsten = 0.004/°C

Therefore, we have;

R₂ = 12×[1 + 0.004×(80 - 15)] = 15.12 ohm

The resistance of the tungsten coil at 80 degrees Celsius = 15.12 ohm.

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