physical properties of metals and non metals with examples

. This gives In the temperature range in which resistivity increases linearly with temperature, the temperature coefficient of resistivity a is defined as the fractional increase in resistivity per unit increase in temperature. Ohm's law is obeyed by many substances, but it is not a fundamental law..

Cathode rays travel in straight lines from the cathode to anode and cast shadow of the object placed in their path. (a) Cathode rays travel in straight lines. Cathode rays consist of an invisible stream of negatively charged particles. When the plates X and Y are given +ve and -ve potent..

Dulong and Petit Law (Specific Heat of Solids) - In 1819, two French physicists Dulong and Petit discovered that the average molar specific heat at constant pressure for all metals, except the very light ones, is approximately the same and equal to nearly 25 J mole -1 o C -1 . Although th..

The minimum amount of energy required to emit electrons from a metal surface is called the work function or threshold energy of that metal. The number of electrons emitted per second i.e. the rate of emission depends upon the material of the surface temperature of the surfa..

Temperature Dependence of Resistivity - The resistivity of a metallic conductor nearly always increases with increasing temperature. As temperature increases, the ions of the conductor vibrate with greater amplitude, making it more likely that a moving electron will collide with an ion. T..

Introduction - In the chapter on current electricity, we had learnt about the flow of charges, conditions to produce the flow and how different materials respond to an external electric field. We had seen how materials are classified as conductors and insulators. In this chapter, we will study a ne..

Practical Applications of Joule's Heating - This heating is inevitable in any electrical circuit. Since the energy lost by the flowing charges ends up as disorderly thermal motion, the phrase 'ohmic dissipation' is also used to describe it. Often, this is an undesirable effect. For example..

A completely satisfactory theory of magnetism has still not been formulated. At present it is assumed that magnetism is due to the movement of the electrons. The electrons circulate around the nucleus of the atom. They also spin around an axis through their centres. These two movements set up magne..

It consists of N turns of coil PQRS wound over a non-magnetic metallic frame usually rectangular or circular. The coil is suspended from a torsion head H by means of phosphor bronze strip in a magnetic pole by pieces N and S. A mirror M is attached to the phosphor bronze strip...

Electrons in different metals can have different energies. If two of these metals are placed in a conducting liquid (electrolyte) a difference in electrical potential is set up between them. A pair of different metals arranged in this way is an electrochemical cell. It..