Physics

Hammering a rod will either allow it to become slightly magnetic if laid along a magnetic field (i.e.North – South) or demagnetise it if laid across the field lines (i.e. East-West). A current passing through a coil will produce a magnetic field.

The paramagnetic theory of magnetism applies to Platinum.

When fast moving electrons strike on high atomic weight substance, X – ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X – ray is the inverse phenomenon of photoelectric effect.

It disconnects the live and neutral wire.

The sources are hydroelectric power plants, thermal power generators,nuclear power generators, AC generators.

When a bottle of perfume is opened in a corner of a room, the scent soon spreads all over the room. This physical procedure is called diffusion, due to which the liquid or gaseous molecules travels from the area of higher density to that of the lower density of that substance.

Red has the longest wavelength.

Air pressure has no effect at all in an ideal gas approximation. This is because pressure and density both contribute to sound velocity equally, and in an ideal gas the two effects cancel out, leaving only the effect of temperature. Sound usually travels more slowly with greater altitude, due to reduced temperature.