Calculate Coil MMF: Step-by-Step Solution

The question asks us to calculate the Magnetomotive Force (MMF) generated in a coil, given the current flowing through it and the number of turns in the coil. We are also provided with the length and thickness of the wire, but these details are not needed for the MMF calculation itself.

Understanding Magnetomotive Force (MMF)

Magnetomotive Force (MMF) is the magnetic equivalent of electromotive force (EMF). It is the driving force that causes magnetic flux to be established in a magnetic circuit. MMF is produced by an electric current flowing through a coil of wire.

MMF Formula

The formula to calculate MMF is:

$$ MMF = N \times I $$

Where:

• $MMF$ is the Magnetomotive Force, measured in Ampere-Turns (AT).
• $N$ is the number of turns in the coil.
• $I$ is the current flowing through the coil, measured in Amperes (A).

Given Values

From the question, we have the following information:

• Current ($I$) = 10 mA
• Number of turns ($N$) = 500
• Length of the wire = 30 mm (Not required for MMF calculation)
• Thickness of wire = 60 mm (Not required for MMF calculation)

Convert Current to Amperes

First, we need to convert the current from milliamperes (mA) to amperes (A):

$$ I = 10 \, \text{mA} = 10 \times 10^{-3} \, \text{A} = 0.01 \, \text{A} $$

Calculating MMF

Now, we can substitute the values of $N$ and $I$ into the MMF formula:

$$ MMF = N \times I $$

$$ MMF = 500 \times 0.01 \, \text{A} $$

$$ MMF = 5 \, \text{AT} $$

Conclusion

The Magnetomotive Force generated in the coil is 5 Ampere-Turns (AT). Comparing this result with the given options, we find that it matches option 2.