\(\mathrm{A}\) coil of inductance \(\mathrm{L}\) has an inductive reactance of \(\mathrm{X}_{\mathrm{L}}\) in an AC circuit in which the effective current is \(\mathrm{I}\). The coil is made from a super-conducting material and has no resistance. The rate at which power is dissipated in the coil is. (a) 0 (b) \(\mathrm{IX}_{\mathrm{L}}\) (c) \(I^{2} \mathrm{X}_{\mathrm{L}}\) (d) \(\mathrm{IX}^{2} \mathrm{~L}\)

Short Answer

Expert verified
The rate at which power is dissipated in the superconducting coil is 0.

Step by step solution

01

Understand the power formula in an AC circuit

In an AC circuit, the total power (P) can be represented as the product of the effective voltage (V) and the effective current (I) and the power factor (pf). The power factor represents the phase angle between the voltage and current in the circuit and can be calculated as: \[pf = \cos(\phi) \] where \(\phi\) is the phase angle between voltage and current. In this case, since the coil has no resistance, the phase angle will be 90 degrees, as the voltage and current are perpendicular to each other in an inductive circuit.
02

Calculate the power factor

Since the phase angle between voltage and current in an inductive circuit is 90 degrees: \[pf = cos(90 ^\circ) = 0\]
03

Calculate the power dissipation in the coil

Using the power formula with the calculated power factor, we can find the power dissipation in the coil: \[P = VI \cdot pf\] \[P = VI \cdot 0\] \[P = 0\]
04

Choose the correct answer

Based on our calculations, the rate at which power is dissipated in the coil is 0. Therefore, the correct answer is: (a) 0

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