Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

One way to determine the inductance of an inductor is to place it in a series ci

ID: 1697466 • Letter: O

Question

One way to determine the inductance of an inductor is to place it in a series circuit with a resistor and capacitor of known values. The circuit is driven by a variable-frequency AC generator with a constant emf, and the frequency is varied until the current through the resistor, as measured by an AC ammeter, reaches a maximum. (a) A circuit like this is used with R = 235 O, C = 1.50×10-5 F, and maximum emf of 145 V. The current reaches a maximum when the frequency is 322 Hz. (a) What is the inductance? (b) What is the maximum current?

A) _______H
B)________A

Explanation / Answer

Given

resistance of the resistor   R = 235

capacitance of the capacitor C = 1.5*10^ -5 F

maximum emf     = 145 V

Frequency   f = 322 Hz

The current reaches at maximum the frequency is resonance frequency

           f = 1 / [2(LC )^(1/2) ]

           (LC )^(1/2) = 1 / 2f  

                             = 1 / 2*3.14* 322

                           L =0.016 H

Maximu m current   I = V / Z

        where

impedance   Z = (R^2 + (X L - XC )^2 ) ^ ( 1 /2 )

                      = ( 235 ^2 )^ (1 /2 )

                   I = V / 235 = 145 /235 =    0.617 A