Remember

Question 1

Why can conduction take place in semiconductor?

Answer 1

There is a small gap between the conduction band and valence band in semi-conductors. As such some of the electrons have enough energy to move from the conduction band to the valence band - as such it can conduct electricity.

Question 2

Effect when potential difference is produced when photons enter the layer between n-type and p-type?

Answer 2

Photovoltaic effect.

Question 3

Most charge carriers are……

Answer 3

Positive

Question 4

Impurity atoms in the p type have …outer electrons

Answer 4

3

Question 5

The p type material has a … charge

Answer 5

Negative

Question 6

In LED electrons drop from ……. band to …… band

Answer 6

Conduction band to valence band

Also mention conduction band in 1st part of answer.

Question 7

Questions regarding using same equipment to obtain better results-

Answer 7

Repeat measurements

Take smaller steps around x value

Question 8

What is meant by a potential difference of 200kv

Answer 8

200000 joules of energy are available to each coulomb of charge

Question 9

What is meant by doped semiconductor

Answer 9

Semiconductor with impurities added to it

Question 10

Why is central maxima white - path difference

Answer 10

Path difference at the central maxima is 0 for each frequency/colour/ wavelength

Question 11

What is meant by alternating current

Answer 11

Current that changes direction and instantaneous value with time