3: Electrical and Electronic Principles.
Task – 1 a
M / m / –
length, kg / kg / -Solid, second / s / -time, ampere / A / – Kelvin / K /
electric current – thermodynamic temperature, mol / mol / – amount of candle
substance / kd / – intensity of the light.
iv-resistance capacity v
c / The
prefixes are used to indicate degrees to ten. It means that with only one unit
of measurement you can express any measure from the smallest to the largest.
Each of them has a short name and a symbol. Big factors have capital letters
and small ones have lowercase letters.
giga 1 000 000 000 G
mega 1,000,000 M
kilogram 1,000 k
the advantages of SI units: why are they a global choice and should they be
used in the design?
No conversion: only one unit for each value
There are no numbers to remember: the
derived units are determined algebraically without numerical factors
There are no long zeros: prefixes are used
to denote degrees of ten
The world standard: all other units,
including the imperial and American British units, are defined by them
It is not static, but is developed to take
advantage of the increased accuracy of measurement standards and the increase
in measurement requirements.
d / i – 0.100245
research is primarily a research study. It is used to understand the main
causes, opinions and motivations. It gives an idea of ??the problem or helps
develop ideas or hypotheses for potential quantitative research. Qualitative
research is also used to identify trends in thinking and opinions and to
investigate the problem.
research is used to quantify the problem by creating numeric data or data that
can be converted into useful statistics. It is used to quantify relationships,
opinions, behaviors and other specific variables and summarizes the results of
a larger sample of the population. Quantitative research uses measurable data
to formulate facts and identify research models. Quantitative data collection
methods are much more structured than quantitative data collection methods.
Quantitative methods for data collection include various forms of surveys:
online surveys, document reviews, mobile surveys and reviews of kiosks,
personal interviews, telephone interviews, longitudinal studies, site
interceptors, online surveys and systematic observations.
measures are those relating to quantity, for example:
The mass of
the sample, the length of a piece of wire, molecules per mole, the volume of
gas, the temperature of the sample – these types of measurements are extensive.
measures are those relating to quality, for example:
of the sample, the consistency of the surface, the roughness of the powder, the
aroma of the reaction, the ductility of the metal. These types of
measurements are called intense.
Task 6 a.
force on an object is equal to the weight of the liquid it moves.
Submarine – has a large ballast tank, which is used to control the position and
depth of the sea surface. A submarine submerges under water in the ballast tank
so that its weight becomes greater than the driving force and it floats by
reducing water in the ballast tank, so that its weight is less than the driving
floats on the surface of the sea because the volume of water that is moved by
the ship is sufficient to have a weight equal to the weight of the ship. A ship
is constructed in such a way that the shape is hollow to make the overall
density of the ship smaller than the seawater. That is why the driving force
that works on the ship is big enough to carry the weight.
balloon. The atmosphere is filled with air that exerts a powerful force on
every object. A hot air balloon rises and floats as a result of the driving
force (when the surrounding air is greater than the weight). It drops when the
weight of the balloon is higher than the driving force. It becomes stationary
when the weight is equal to the driving force.
liquids and gases have different properties. Liquids and gases can flow. Solid
bodies keep their shape. Gases can be shattered. Stay solid in a new place and
can be retained, retain their shape, always occupy the same amount of space,
can be cut or formed. Heating some solids can turn them into liquids – butter
in a pan or cool, a liquid can make a solid – the water frozen in ice cubes.
easily be poured or poured, they are not easy to hold, their exchange shape in
anticipation of the container always takes up the same amount of space. Heating
a liquid can change it to gas / boiling water, cooling a liquid can turn it
into a solid, heating a solid can turn it into a liquid / burning candle.
are often invisible, do not retain their shape or always occupy the same amount
of space. They spread and change their shape and volume to fill up any
container they are in. Gases can be shattered. Heating a liquid can turn it
into a gas – steam from the boiler.
It is well
known that thermal welding voltages and resulting residual stresses affect the
strength of the welded structure, causing problems such as brittle fracture,
kinking and weld fractures. At the time of welding, a limited part of the
welded joint is heated to a very high temperature and cooled to room
temperature. In the thermal cycle that takes place, the temperature
distribution changes over time and affects the mechanical properties of the
metals. To perform a reliable theoretical analysis, the above factors must be
taken into account. In daily life, construction, engineering, scientists must
consider the influence of many factors on metal structures such as the
atmosphere at a particular place, the ambient temperature or the environment in
which a particular structure will be placed. One of these factors is the effect
of temperature on metals, because it is known how much they are sensitive to
high temperatures when it can stretch or also to low temperatures when metals
can shrink significantly and reduce their volume. A good example is the construction
of bridges engineers have to construct them in such a way that the structure
can work freely at great distances, i.e. to extend and reduce the required
distances between the links of the bridge. Another example is rail rails, when
we look at the rail connection constructions, we can see that the builder
leaves free space between the rail connections because the friction force of
the rail cars on the rail causes the heating of the rails, which results in
stretching if they do not leave the rails. rail space that overlaps, resulting
in the derailment of the train.
P6. Metals – heat and electricity
that conduct heat and electricity, usually characterized by toughness, positive
resistance coefficient, opacity and characteristic gloss. Non-metallic –
chemical elements that are poor conductors of electricity (insulators or
semiconductors) and usually also heat (a clear exception here is a diamond). In
the solid state they are fragile and without metallic
of materials degradation the deterioration of a material due to reaction with
the environment. All materials are degraded on the surface to varying degrees
when subjected to: Sunshine, liquids (water, solvent oil), oxygen gas, metals.
Wooden materials under the influence of biological organisms, fungi, insects,
water, so that wood swells and shrinks. Plastic materials are not degraded in
general, but UV light is weakening certain plastics and produce a cretaceous
appearance of fading on the surface. Heat some plastics weaken or melt, cold
some plastics can brittle and break under pressure, mold can grow moist on
plastic, humid conditions.
ferrous metals, such as steel, are particularly susceptible to oxidation and
require continuous maintenance, or they suffer inevitable structural defect
number of non-ferrous metals are particularly resistant to corrosion, for
example, copper and zinc copper coating zinc coating. Most corrosion of ferrous
metals occurs by electrochemical reaction. This is also known as wet corrosion.
Electrochemical corrosion can occur when two different metals are in contact
and an electrolyte solution is present. Degradation of the metal effects of
corrosion on mechanical and physical properties, reduction of metal thickness,
leading to loss of strength or all structural failure, local corrosion leads
structures “crack-like” that weakens the metal.
Task 15 a
Task 15 b.
Task 16 a /