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A precision laboratory resistor is made of a coil of wire. The coil is 1.5 cm in diameter, 2.5 cm long, and has 500 turns. What is the resistance of the coil?

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Final answer:

The resistance of the coil is 2.40 ohms.

Step-by-step explanation:

The resistance of the coil can be calculated using the formula:

R = (rho * l) / A

Where:

  • R is the resistance
  • rho is the resistivity of the material (depends on the material used for the coil)
  • l is the length of the coil
  • A is the cross-sectional area of the coil

Since the coil is made of wire, we can assume the resistivity of copper, which is 1.68 x 10^-8 ohm*m. The length of the coil is 2.5 cm, converted to meters is 0.025 m. The cross-sectional area can be calculated using the formula A = pi * r^2, where r is the radius of the coil. The radius can be calculated by dividing the diameter by 2. So, the radius is 1.5 cm / 2 = 0.75 cm, converted to meters is 0.0075 m. The cross-sectional area is then pi * (0.0075 m)^2 = 1.767 x 10^-4 m^2.

Substituting the values into the formula, we get:

R = (1.68 x 10^-8 ohm*m * 0.025 m) / (1.767 x 10^-4 m^2) = 2.40 ohms.

Therefore, the resistance of the coil is 2.40 ohms.

User Buk Lau
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