What value of inductance will provide an $X_\text{L}$ of $500\space\Omega$ at a frequency of $159.15\text{ kHz}$? a. $5\text{ H}$. b. $500\space\mu\text{H}$. c. $500\space\text{mH}$. d. $750\space\mu\text{H}$.

For a steady dc current, the $X_\text{L}$ of an inductor is a. infinite. b. extremely high. c. usually about $10\text{ k}\Omega$. d. $0\space\Omega$.

The inductive reactance, $X_\text{L}$, of an inductor is a. inversely proportional to frequency. b. unaffected by frequency. c. directly proportional to frequency. d. inversely proportional to inductance.

The unit of inductive reactance, $X_\text{L}$, is the a. henry. b. ohm. c. farad. d. hertz.

The inductance, $L$, of an inductor is affected by a. number of turns. b. area enclosed by each turn. c. permeability of the core. d. all of the above.

Calculate the inductive reactance, $X_\text{L}$, of a $100\text{-mH}$ inductor at the following frequencies: a. $f=60\text{ Hz}$. b. $f=120\text{ Hz}$. c. $f=1.592\text{ kHz}$. d. $f=10\text{ kHz}$.

Referring to Fig. 20–4, how does this graph show a linear proportion between $X_\text{L}$ and $L$?

Referring to Fig. 20–3, how does this graph show a linear proportion between $X_\text{L}$ and frequency?

In Fig. 20–10, how much is the inductive reactance, $X_\text{L}$, for each of the following values of $Vac$ and $I$? a. $Vac=10\text{ V}$ and $I=2\text{ mA}$. b. $Vac=50\text{ V}$ and $I=20\space\mu\text{A}$. c. $Vac=12\text{ V}$ and $I=15\text{ mA}$. d. $Vac=6\text{ V}$ and $I=40\space\mu\text{A}$. e. $Vac=120\text{ V}$ and $I=400\text{ mA}$.

In Fig. 20–10, how much is the inductive reactance, $X_\text{L}$, for each of the following values of $Vac$ and $I$? a. $Vac=10\text{ V}$ and $I=2\text{ mA}$. b. $Vac=50\text{ V}$ and $I=20\space\mu\text{A}$. c. $Vac=12\text{ V}$ and $I=15\text{ mA}$. d. $Vac=6\text{ V}$ and $I=40\space\mu\text{A}$. e. $Vac=120\text{ V}$ and $I=400\text{ mA}$.

Why are the waves in Fig. 20–7 a and b considered $90^{\circ}$ out of phase, whereas the waves in Fig. 20–7 b and c have the same phase?

How much is the capacitance of a capacitor that draws $2\text{ mA}$ of current from a $10\text{-Vac}$ generator whose frequency is $3.183\text{ kHz}$?

In Fig. 20–9, the ammeter, $M_1$, reads an ac current of $25\text{ mA}$ with $S_1$ in position $2$. a. Why is there less current in the circuit with $S_1$ in position $2$ compared to position $1$? b. How much is the inductive reactance, $X_\text{L}$ , of the coil? (Ignore the effect of the coil resistance, $r_\text{i}$.)

A very common use for a capacitor is to a. block any dc voltage but provide very little opposition to an ac voltage. b. block both dc and ac voltages. c. pass both dc and ac voltages. d. none of the above.