Page 553 - SUBSEC October 2017_Neat

UNIT 2
MODULE 2: A C THEORY AND ELECTRONICS (cont’d)

SPECIFIC OBJECTIVES EXPLANATORY NOTES SUGGESTED PRACTICAL
ACTIVITIES

Alternating Currents (cont’d)

Students should be able to:

1.4. discuss the advantages of The role of step up and step Record the highest voltages
using alternating current down transformers in the observed on electrical
and high voltages for the transmission of electrical transformers in their
transmission of electrical power should be neighbourhood.
energy. mentioned.
The magnitudes of
transmission voltages and
associated safety concerns
should be included.

2. The p-n Junction Diode

Students should be able to:

2.1. describe the electrical The population density of
properties of holes and electron in
semiconductors; intrinsic and doped
semiconductors should be
mentioned and compared
with that for conductors.

Resistivity of
semiconductors should be
compared to that of
conductors in order to place
the values in meaningful
contexts.

2.2. distinguish between p- type
and n-type material;

2.3. explain the formation of a The fact that a depletion
depletion layer at a p-n layer forms in the unbiased
junction; p-n junction should be
emphasised.

2.4. discuss the flow of current
when the p-n junction diode
is forward-biased or reverse-
biased;

CXC A16/U2/17 53