Lenz's Law

Lenz's law might have been predicted from the prin­ciple of the conservation of energy. When you move a mag­net toward a coil and thus induce a current in its windings, the induced current heats the wire. In order to supply the energy to do this, you must do work in overcoming an oppos­ing force. If the force did not oppose the motion, you would create energy. Thus the magnetic field of the induced current is seen to oppose the change.

Lenz's law and the right hand rule can be used to de­termine the direction of an induced current. The north pole of a magnet being moved closer to a coil, the induced cur­rent causes a field which opposes the motion, a north pole being produced on the nearer face. To cause this north pole, magnetic lines must emerge from this face of the coil. Now grasp the coil with your right hand, so that your fingers point in the direction of the induced magnetic field. Your thumb will point in the direction of the current, that is, counterclockwise.

The Induced Current Opposes the Change. A magnet pole being moved toward one face of a coil, the current induced in the coil produces a magnetic field. Moreover, this field always opposes the change of magnetic flux that is occurring. For example, move the north pole of a magnet closer to one face of a coil. The induced current will be counterclockwise and will oppose the change of flux through the coil. Remove the bar magnet, and the induced current in the coil will be clockwise, again opposing the change. This rule is expressed by Lenz's law, as follows:

Whenever a current is induced, its magnetic field op­poses tlie change of flux.

S. P. Korolyov

The name of the outstanding Soviet scientist academi­cian Sergey Pavlovich Korolyov will forever be linked with the dawn of man's exploration of space. His professional carrier started by designing a glider. When he was 24 he graduated from higher technical school, became a glider designer and finished a flying school. He read K. Tsiolkovsky's works and was captivated by the ideas in them. S. Korolyov devoted to rocket-engineering all his great talent and scientific insight based on a deep theoretical knowledge associated with practice. His hobby — designing gliders helped him very much in this. S. Korolyov installed the first jet engine of unusual construction on a tailless glider designed by B. Charanovsky. He soon designed another more durable glider which was to be the beginning of the rocket plane. He tested the engine himself which meant taking great risks since breakdowns did happen.

Years passed and S. Korolyov's rare talents developed and matured.

Then it was on October 4, 1957 that a rocket system evolved under his guidance put the first sputnik into orbit round the Earth, all the subsequent stages in space explora­tion going on with his direct participation.

Then came the morning of April 12, 1961. The first man­ned spaceflight was a worthy consummation of all the work on space conquest that had preceded it.

Academician S. Korolyov is known to have been a great scientist and designer. Those who worked with him say that it was always interesting to listen to him even though, he mostly spoke in engineering formulae.

His amazingly dynamic thought thrilled, even charmed his audience and the iron logics of his arguments sounded utterly convincing.