Let the total resistance of the circular coil be R. The resistance of each semicircle is R/2. When these two semicircles are connected in parallel, the equivalent resistance (R_eq) is given by the formula for resistors in parallel: 1/R_eq = 1/R₁ + 1/R₂. Here, R₁ = R₂ = R/2. So, 1/R_eq = 1/(R/2) + 1/(R/2) = 2/R + 2/R = 4/R. Therefore, R_eq = R/4.
A circular coil of single turn has a resistance of 20 Ω. Which one of the following is the correct value for the resistance between the ends of any diameter of the coil?
Asked in UPSC NDA 1 2017 · Topic: Electric Current (Series and parallel combination of resistors)
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