At short circuit of a chain the condenser starts being discharged via the coil: there is a current and the related magnetic field. Owing to a self-induction current increases gradually; energy of electric field will be transformed to energy of a magnetic field
In a subject "Electromagnetic oscillations" the electromagnetic process arising at a condenser discharge via the coil of inductance is considered and the conclusion about oscillatory nature of this process is drawn.
On these models consider back and forth motion of the pump (or rotation the pump that in one, in other party; thus the elastic membrane caves in in the relevant parties. There is a movement of liquid in pipes (current), but liquid does not pass through a membrane as well as charges in an electric chain do not pass through condenser dielectric.
Therefore the similar mechanical system will represent attached to a spring (rigidity To) a body with very small weight, but with a considerable volume, ß which is in an action field of power of viscous friction with coefficient.
At introduction of concept about electric current the analogy to a current of water in the turbine is useful. The analogy becomes especially figurative if by this time the concept about an electron is entered, then electric current is represented as the ordered movement of electrons in the conductor. The hydrodynamic analogy is very useful and at acquaintance to current sources. On poles of a source of current tension is created. Charges (electrons, ions) which move in conductors (metals, electrolytes), are available in conductors. They move chaotically but if to attach the conductor to current source poles, charges will come to the ordered movement, that is there will be a current.
Strengthening of power on tension is based on distinction of resistance of collector and emitter p - n - the transitions included in opposite directions. Emitter transition on which the direct tension of shift is given, has the small resistance, and power failure of Us on it it is not enough. On collector transition the return tension of shift, and its resistance moves much more therefore the collector chain can include high-resistance loading, Rn which resistance much more resistance of emitter transition. As Ik and Ie are identical, power failure on high-resistance collector loading of Un=ikriern will appear much more power failure on emitter transition.
Comparison is the cornerstone of analogy. If it is found out that two or more objects have similar signs, the conclusion and about similarity of some other signs is drawn. The conclusion by analogy can be both true, and false therefore it demands experimental check.
Analogies between mechanical and electric oscillatory processes to success are used in modern researches and calculations. At calculation of difficult mathematical systems often resort to electromechanical analogy, modeling mechanical system of the corresponding electric.
Two usual light sources are not coherent. Pupils need to explain that for receiving a steady picture of an interference of light it is necessary to use special installations in which force to interfere two bunches of the same wave radiated by one source, but going to a supervision point various ways.
The analogy between inductance in a chain of alternating current and the mass of a material body is useful to inductive resistance. In case of alternating current the electromotive force of a self-induction takes place in a chain all the time, but does not arise only at the time of inclusion and switching off of current as it was in case of a direct current. Presence of this.. . also explains emergence of induction resistance.
Then explain that at the maximum value of tension current is equal in a chain to zero and vice versa. For this purpose on mechanical analogy is shown that at the maximum value of the operating force speed is equal to zero and when speed is maximum, equal to zero the operating force.
After that show an interference of light and by analogy explain an interferential picture. Drawing an analogy between light and superficial water waves, show similarity and distinction of the phenomena of various nature.