Question

At what frequency will a 18.0mH inductor have a reactance of 620? ?

Express your answer using two significant figures.

Answer 1

given that :

inductance, L = 18 mH = 18 x 10^-3 H

inductive reactance, X_L = 620 H

now, using a formula :

X_L = L                                   { eq. 1 }

where, = 2 f

inserting the value of '' in above eq.

X_L = (2 f) L

f = X_L / 2 L                            { eq. 2 }

inserting the values in eq.2,

f = (620 H) / 2 (3.14) (18 x 10^-3 H)

f = 620 x 10³ / 113.04

f = 5.48 kHz

or f = 5.5 kHz                     (Answer in two significant figure)