This will cover chapter one and two of medical physics.Slides to help students in electrotherapy medical physics part.will cover part from the book and internet source includes Thermal effect of current Chemical effects Cell/batteries Electronic tube Diodes Triodes Electrolysis Electrical burns

1. medical physics
by dr maida

2. electrical components of current
• electric current
• the flow of charge in a conductor is called EC
• essentials for the production of current
1. potential difference
2. pathway along with CURRENT CAN MOVE.

3. current carriers
• charged particles whose flow in a definite direction
constitutes the electric current called CC.
• CC in solids
• e.g metals because of thier valence electron
because it do not remain attach to the atoms but move
freely in conductor
• CC in liquid
• positively and negetively charged ions.
• CC in gases
• they are insulators but can be conductor by ionizing when
applied a high potential difference at low pressures
(because ionized gas contain postive and negetive ion)

7. energy is the ability to do
work.energy can niether be
produce nor can be destoyed
but can covert from one form
to another.

8. chemical effects of current
• when current is passed through solid it will produe
heating effect and magnetic field but no chemical effect
will produce
• on the other hand on liquids
• it may or may nor allow current to pass
• divided into 3 categories
• insulators (do not allow crrent to pass e.g vegetable oil
distilled water),good conductors(current can pass but
do not dissociate into ion e.g mercury
• electrolytes can dissociate into ions salts acids basis
alcohol.

12. cell
• devise by which chemical
energy is converted into
chemical energy
• types
• 2
• primary
• secondary /storage cells

13. primary secondary
• voltalic cell
• daniel cells
• leclanche cell
• dry cell
• lead acid accumulator
• alkali accumulator /edison
cell

14. voltalic cell
• A voltaic cell is an
electrochemical cell that
uses a chemical reaction
to produce electrical
energy.

15. daniel cell
• A Daniell cell is the best
example of a galvanic cell
which converts chemical
energy into electrical energy.
The Daniell cell consists of
two electrodes of dissimilar
metals, Zn and Cu; each
electrode is in contact with a
solution of its own ion; Zinc
sulphate and copper
sulphate respectively.

17. • In a lead-acid accumulator,
the anode and cathode are
made of lead dioxide and
lead respectively. The
electrolyte is dilute
sulphuric acid. As power is
discharged from the
accumulator, both the
anode and cathode
undergo a chemical
reaction that progressively
changes them into lead
sulphate

18. • Alkaline batteries are used
in many household items
such as MP3 players, CD
players, digital cameras,
toys, flashlights, and
radios.

19. advantages of alkali accumulator

20. disadvantage

21. • The cells are said to be
connected in series if the
positive terminal of the first
cell is connected to the
negative terminal of the
second cell and the
negative terminal of the
second cell is connected
to the positive terminal of
the third cell. The same
current flows through each
cell.
• Cells are in parallel
combination if the current
is divided among various
cells. In a parallel
combination, all the
positive terminal are
connected together and all
the negative terminal are
connected together.

22. electronic tube
An electron tube (also known as a 'Vacuum tube', or
a 'Valve' ) is a glass or metal enclosure in which
electrons move through the vacuum or gas from one
metal electrode to another. The vacuum tube is often
used to amplify weak currents or act as a one-way
valve (rectifier) for electric current.
types
slow wave
fast wave

23. Electrolysis
• Electrochemical cell which
convert electrical energy
into chemical energy is
called as electrolytic cell.
Electrochemical cell which
converts chemical energy
into electrical energy is
called as Galvanic or
Voltaic cell.
• Electrical burns and
injuries happen when
electric currents pass
through the body. The
currents can damage the
skin, tissues, and major
organs. The damage can
range from minor to
severe. Sometimes it is
fatal.

24. The most common shock-related, nonfatal injury is a burn. Burns caused by
electricity may be of three types: electrical burns, arc burns, and thermal contact
burns. Electrical burns can result when a person touches electrical wiring or
equipment that is used or maintained improperly.

25. slow wave devises
• diode
• triode
• a semiconductor device
with two terminals,
typically allowing the flow
of current in one direction
only.
• electron tube consisting of
three electrodes—cathode
filament, anode plate, and
control grid—mounted in
an evacuated metal or
glass container. It has
been used as an amplifier
for both audio and radio

26. Thank
You