# Self-Induction

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Related to Self-Induction: Coefficient of coupling

## self-induction

[¦self in¦dək·shən]
(electromagnetism)
The production of a voltage in a circuit by a varying current in that same circuit.

## Self-Induction

the appearance of an electromotive force (emf) of induction in a conducting circuit when the current in the circuit changes. This phenomenon is a special case of electromagnetic induction. The current change in the circuit causes a change in the magnetic flux through the surface enclosed by the circuit. As a result, an emf—the emf of self-induction—is induced in the circuit. The direction of the emf is determined by Lenz’s law: if the current in the circuit increases, the emf of self-induction opposes this increase; if the current decreases, the emf opposes the decrease. Thus, self-induction is similar to the phenomenon of inertia in mechanics. The emf of self-induction eL is proportional to the rate of change of the current i and to the self-inductance L of the circuit: eL = - Ldi/dt.

Because of self-induction, the closing of an electric circuit containing a constant emf does not instantaneously establish a steady current; the current is established only after a certain time interval (see TRANSIENT). Similarly, when the circuit is opened, the current flow does not cease instantaneously. The emf of self-induction that is induced by the opening of the circuit can be several times greater than the emf of the source. In AC circuits, the emf of self-induction causes the current in an inductance coil to lag in phase behind the voltage across the ends of the coil by (see ALTERNATING CURRENT).

The phenomenon of self-induction plays an important role in electrical engineering and radio engineering. Self-induction causes the recharging of a capacitor connected in series with an inductance coil (see OSCILLATORY CIRCUIT); as a result, natural electromagnetic oscillations are established in the circuit.

### REFERENCE

Kalashnikov, S. G. Elektrichestvo. Moscow, 1970. (Obshchii kurs fiziki, vol. 2.)

G. IA. MIAKISHEV

References in periodicals archive ?
Restrictions on medication abortion, both as self-induction through misoprostol alone and restrictions on ingesting medication at home under doctor supervision, increase the scrutiny of pregnant people, including those suffering poor pregnancy outcomes unrelated to the use of medication abortion.
102) For pregnant people in these communities, abortion self-induction in the home offers greater protection from governmental surveillance that particularly targets communities of color living in poverty.
We describe the prevalence and practices of unsuccessful attempts at self-induction and related factors among women presenting without complications and seeking second-trimester abortion at public health facilities in the Western Cape.
A priori factors identified for potential association with self-induction included age, education, socioeconomic status, home language, parity, previous abortions, gestational age according to ultrasound scan, and care-seeking experiences.
The purpose of this qualitative study was to explore experiences of abortion self-induction by women living in the US, to better understand women's motivations and suggest practice and policy recommendations to improve access to safe abortion care.
The sites were selected to oversample Latinas and low-income women, since prior reports have documented self-induction with misoprostol among these populations in the US.
Next the influence of wave height to the self-induction and sensitiveness of inductive coil was investigated.
That results in changes of self-induction within the sensor.
If self-induction failed outside help would be sought.
there are two recent changes that may be leading the incidence of self-induction to increase.
In a 2012 survey of 318 women seeking abortion in Texas, researchers with the Texas Policy Evaluation Project found comparatively high rates of attempts to self-induce: 7 percent of Texas women surveyed, and 12 percent of women surveyed in the Rio Grande Valley, attempted self-induction before going to an abortion clinic, compared with 2.
The confluence of extremely limited access to abortion in the context of poverty, access to misoprostol from Mexico, as well as familiarity with the practice of self-induction in Latin America, makes it particularly likely that self-induction will become more commonplace in Texas," the researchers wrote in an article published in October in Contraception, an international reproductive health journal.

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