What the help of a diagram, show that biasing of a light emitting diode (LED). Give its two advantages over conventional incandescent lamps.

What is light emitting diode (LED)?

Explain, with the help of a schematic diagram, the principle and working of a Light Emiting Diode. What criterion is kept in mind while choosing the semiconductor material for such a device ? Write any two advantages of light emiting diode over conventional incandescent lamps.

What do you mean by light emitteing diodes? Why are they so called? State applications of LEDs. Why we prefer LEDs over conventional incandescent lamps?

Two similar bars made from two different materials P and Q are placed one by one in a non-uniform magnetic field. It is observed that bar P tends to move from the weak to the strong field region and d. What is the nature of the magnetic materials for making these two bars? Show with the help of a diagram, the behaviour of the field lines due to an external magneic field near each of these two bars.

What is meant by dispersion of light explain with the help of diagram and give the cause of dispersion

A die is numbered in such a way that its faces show the numbers 1, 2, 2, 3, 3, 6. It is thrown two times and the total score in two throws is noted. Complete the following table which gives a few values of the total score on the two throws : : What is the probability that the total score is : at least 6 ?

A die is numbered in such a way that its faces show the numbers 1, 2, 2, 3, 3, 6. It is thrown two times and the total score in two throws is noted. Complete the following table which gives a few values of the total score on the two throws : : What is the probability that the total score is : even ?