physics reasoning questions

(i) The combination of the F 1 and F 2 layers into one F layer (ii) The virtual disappearance of the other two layers, which were causing noticeable absorption during the d..

The velocity of electromagnetic waves is 3 x 10 8 ms - 1 . On the other hand, the velocity of sound waves cannot be used to transmit intelligence to far off places. Only electromagnetic waves can be made to do this. Modulation is extremely necessary in communication systems due to the following ..

As such substances are subjected to cyclic changes the loss of magnetic properties of substance must be small. Therefore the material should attain high values of intensity of magnetisation I and magnetic field for low values of the external field which is the magnetising field. For this reaso..

The fact that chemical changes produce electrical effect was discovered accidentally in 1971, by Luigi Galvani, an Italian professor. He found that an electric current flowed across two dissimilar metals. Volta, professor of natural philosophy successfully reproduced some of Galvani's results using..

Sliding friction opposes the applied force and has a constant value. Normal reaction and force of sliding friction are proportional quantities. Keeping normal reaction constant, the frictional force is independent of the surface area in contact. For reasonable velocities, the v..

Materials for making permanent magnet should possess high residual magnetism i.e., when the magnetising field is reduced to zero, the intensity of magnetisation is high. Further, to reduce the residual magnetism to zero, the magnetising field should be applied in the opposite direction. The greater..

Need for Modulation - The velocity of electromagnetic waves is 3 x 10 8 ms - 1 . On the other hand, the velocity of sound waves cannot be used to transmit intelligence to far off places. Only electromagnetic waves can be made to do this. Modulation is extremely necessary in communication systems du..

ticed that whenever the body was dropped on a slope from a certain height, it always rose to almost the same height on the other slope. As friction decreased on the surfaces, the body rose closer to the same height and when friction was almost zero, it rose to the same height. Hence, he reaso..

Chemical Effect of Current - The fact that chemical changes produce electrical effect was discovered accidentally in 1971, by Luigi Galvani, an Italian professor. He found that an electric current flowed across two dissimilar metals. Volta, professor of natural philosophy successfully reproduced so..

The skip distance is the shortest distance from a transmitter, measured along the surface of the Earth, at which a sky wave of fixed frequency (more than f c ) will be returned to Earth. One expects there to be a maximum distance, as limited by the curvature of the Earth, but nevertheless a definit..