In Fig. 19–36, calculate the primary current, $I_\text{P}$, if $R_{\text{L}_1}$ opens.

A coil, $L_1$, produces $200\space\mu\text{Wb}$ of magnetic flux. A nearby coil, $L_2$, is linked with $L_1$ by $50\space\mu\text{Wb}$ of magnetic flux. What is the coefficient of coupling, $k$, between $L_1$ and $L_2$?

How much is the self-induced voltage across a $33\text{-mH}$ inductance when the current changes at the rate of $1500\space\frac{\text{A}}{\text{s}}$?

Calculate the inductance, $L$, for the following long coils: (Note: $1\text{ m}=100\text{ cm}$ and $1\text{ m}^2=10,000\text{ cm}^2$.) a. air core, $20$ turns, area $3.14\text{ cm}^2$, length $25\text{ cm}$. b. same coil as step a with ferrite core having a $\mu_\text{r}$ of $5000$. c. air core, $200$ turns, area $3.14\text{ cm}^2$, length $25\text{ cm}$. d. air core, $20$ turns, area $3.14\text{ cm}^2$, length $50\text{ cm}$. e. iron core with $\mu_\text{r}$ of $2000$, $100$ turns, area $5\text{ cm}^2$, length $10\text{ cm}$.

If the bleeder current, $I_\text{B}$, is $15\text{ mA}$ in Fig. 7–32, solve for a. $I_1$, $I_2$, $I_3$, and $I_\text{T}$. b. $V_1$, $V_2$, and $V_3$. c. $R_1$, $R_2$, and $R_3$. d. The power dissipated by $R_1$, $R_2$, and $R_3$.

In Fig. 19–36, solve for a. $V_{\text{S}_{1}}$ (secondary 1 voltage). b. $V_{\text{S}_{2}}$ (secondary 2 voltage). c. $I_{\text{S}_{1}}$ (secondary 1 current). d. $I_{\text{S}_{2}}$ (secondary 2 current). e. $P_{\text{Sec}_{1}}$. f. $P_{\text{Sec}_{2}}$. g. $P_{\text{pri}_{1}}$. h. $I_\text{P}$.

Evaluate the given partial integral. $\int_{1}^{2} \tan x y\ d y$

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.

State Lenz’s law in terms of induced voltage produced by varying current.

The secondary current, $I_\text{s}$, in an iron-core transformer equals $1.8\text{ A}$. If the turns ratio, $\dfrac{\text{N}_\text{P}}{\text{N}_\text{S}}$, equals $3:1$, how much is the primary current, $I_\text{P}$? a. $I_\text{P}=1.8\text{ A}$. b. $I_\text{P}=600\text{ mA}$. c. $I_\text{P}=5.4\text{ A}$. d. none of the above.

In Fig. 19–35, solve for a. the secondary voltage, $V_\text{S}$. b. the secondary current, $I_\text{S}$. c. the secondary power, $P_\text{sec}$. d. the primary power,$P_\text{pri}$. e. the primary current, $I_\text{P}$.

How much is the induced voltage, $V_\text{L}$, across a $5\text{-H}$ inductor carrying a steady dc current of $200\text{ mA}$? a. $0\text{ V}$. b. $1\text{ V}$. c. $100\text{ kV}$. d. $120\text{ Vac}$.

How much is the induced voltage, $V_\text{L}$, across a $5\text{-H}$ inductor carrying a steady dc current of $200\text{ mA}$? a. $0\text{ V}$. b. $1\text{ V}$. c. $100\text{ kV}$. d. $120\text{ Vac}$.

Two inductors, $L_1$ and $L_2$, have a coefficient of coupling, $k$, equal to $0.5$. $L_1=100\text{ mH}$ and $L_2=150\text{ mH}$. Calculate $L_\text{M}$.