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+====== Block 01 — Physical quantities and SI system ======
+===== Learning objectives =====
+<callout>
+After this 90-minute block, you can
+  * Use the SI base quantities, units, and symbols correctly; convert between units with prefixes.
+  * Distinguish base vs. derived quantities; express key EE units (e.g. $\rm V$, $\rm \Omega$) in SI base units.
+  * Apply quantity equations and perform unit (dimensional) checks; contrast with normalized (dimensionless) equations.
+  * Read and use common Latin/Greek letter symbols; distinguish uppercase/lowercase and instantaneous vs. constant quantities.
+</callout>
+===== 90-minute plan =====
+  - Warm-up (10 min):
+    - “What is the unit of conductivity? of energy?”
+	- Quick prefix quiz; everyday magnitude estimates ($\rm mA$, $\rm k\Omega$, $\rm \mu F$).
+  - Core concepts & derivations (60 min):
+    - SI base set → derived units; prefix rules;
+	- quantity vs. normalized equations;
+	- dimensional checks.
+    -  Prefix ladder ($\rm E$…$\rm a$) and best-practice rounding/checks.
+    - Symbols & Greek letters in EEE1; time-varying vs constant symbols.
+  - Practice (15 min): Fast conversions and unit checks (individual → pair).
+  - Wrap-up (5 min): Summary table; common pitfalls checklist.
+===== Conceptual overview =====
+<callout icon="fa fa-lightbulb-o" color="blue">
+  - Units are the grammar of engineering and physics.
+  - The SI defines seven **base quantities** and units; all other (derived) units are built from these without extra numerical factors. The SI defines seven **base quantities** and units.
+  - In EEE1 we work strictly in the SI system, combining **numerical value × unit** and tracking dimensions at every step (e.g., $I=2~\rm A$ means “two times one ampere”).
+  - Derived units (e.g., $\rm V$, $\rm \Omega$, $\rm S$) must reduce to base units without hidden factors.
+  - **Prefixes** scale units by powers of ten to keep numbers readable. Prefixes compress very large and very small numbers so we can compute and compare safely.
+  - **Quantity equations** keep units; **normalized equations** cancel units to yield dimensionless ratios (e.g., efficiency).
+  -   In EE, symbol choices and letter case matter: $U$ vs. $u(t)$, $\rm M$ (mega) vs. $\rm m$ (milli). We adopt a consistent symbol set (Latin + Greek), and distinguish **constants** (capital letters) from **time functions** (lowercase, e.g., $u(t)$).
+  - Finally, we preview the three anchor quantities for the next blocks: **charge** (what moves), **current** (how fast charge moves), and **voltage** (energy per charge). Physics describes **quantities** with a **numerical value × unit** (e.g., $I=2~\rm{A}$).
+  </callout>
+===== Core content =====
+==== SI base quantities and units ====
+<WRAP right 50%>
+<tabcaption baseSI| SI base quantities (SI) >
+^ Base quantity           ^ Name      ^ Unit         ^ Definition                       ^
+| Time                    | Second    | ${\rm s}$     | Oscillation of $Cs$-Atom         |
+| Length                  | Meter     | ${\rm m}$     | by s und speed of light          |
+| el. Current             | Ampere    | ${\rm A}$     | by s and elementary charge       |
+| Mass                    | Kilogram  | ${\rm kg}$    | still by kg prototype            |
+| Temperature             | Kelvin    | ${\rm K}$     | by triple point of water         |
+| amount of \\ substance  | Mol       | ${\rm mol}$   | via number of $^{12}C$ nuclides  |
+| luminous \\ intensity   | Candela   | ${\rm cd}$    | via given radiant intensity      |
+</tabcaption>
+</WRAP>
+  * For practical applications of physical laws of nature, **physical quantities** are put into mathematical relationships.
+  * There are basic quantities based on the SI system of units (French for Système International d'Unités), see below.
+  * In order to determine the basic quantities quantitatively (quantum = Latin for //how big//), **physical units** are defined, e.g. ${\rm metre}$ for length.
+  * In electrical engineering, the first three basic quantities (cf. <tabref baseSI> ) are particularly important. \\ Mass is important for the representation of energy and power.
+  * Each physical quantity is indicated by a product of **numerical value** and **unit**: \\ e.g. $I = 2~{\rm A}$
+    * This is the short form of $I = 2\cdot 1~{\rm A}$
+    * $I$ is the physical quantity, here: electric current strength
+    * $\{I\} = 2 $ is the numerical value
+    * $ [I] = 1~{\rm A}$ is the (measurement) unit, here: ${\rm Ampere}$
+~~PAGEBREAK~~ ~~CLEARFIX~~
+==== Common derived quantities ====
+  * Besides the basic quantities, there are also quantities derived from them, e.g. $[F] = [m]\cdot [a] \rightarrow 1~{\rm N} = 1 ~{\rm kg} \cdot {{1 ~{\rm m}}\over{1 ~{\rm s}^2}}$.
+  * SI units should be preferred for calculations. These can be derived from the basic quantities **without a numerical factor**. \\ example:
+    * The pressure unit bar (${\rm bar}$) is an SI unit.
+    * BUT: The obsolete pressure unit "Standard atmosphere" ($=1.013~{\rm bar}$) is **__not__** an SI unit.
+  *  To prevent the numerical value from becoming too large or too small, it is possible to replace a decimal factor with a prefix.
+We will see, that a lot of electrical quantities are derived quantities.
+==== Prefixes ====
+<WRAP right 50%>
+<tabcaption prefix1 | Prefixes I>
+^ prefix ^ prefix symbol ^ meaning^
+| Yotta  | ${\rm Y}$      | $10^{24}$   |
+| Zetta  | ${\rm Z}$      | $10^{21}$   |
+| Exa    | ${\rm E}$      | $10^{18}$   |
+| Peta   | ${\rm P}$      | $10^{15}$   |
+| Tera   | ${\rm T}$      | $10^{12}$   |
+| Giga   | ${\rm G}$      | $10^{9}$    |
+| Mega   | ${\rm M}$      | $10^{6}$    |
+| Kilo   | ${\rm k}$      | $10^{3}$    |
+| Hecto  | ${\rm h}$      | $10^{2}$    |
+| Deka   | ${\rm de}$     | $10^{1}$    |
+</tabcaption>
+<tabcaption prefix2 | Prefixes II>
+^ prefix ^ prefix symbol ^ meaning^
+| Deci   | ${\rm d}$      | $10^{-1}$   |
+| Centi  | ${\rm c}$      | $10^{-2}$   |
+| Milli  | ${\rm m}$      | $10^{-3}$   |
+| Micro  | ${\rm u}$, $µ$  | $10^{-6}$   |
+| Nano   | ${\rm n}$      | $10^{-9}$    |
+| Piko   | ${\rm p}$      | $10^{-12}$  |
+| Femto  | ${\rm f}$      | $10^{-15}$   |
+| Atto   | ${\rm a}$      | $10^{-18}$   |
+| Zeppto | ${\rm z}$      | $10^{-21}$   |
+| Yocto  | ${\rm y}$      | $10^{-24}$   |
+</tabcaption>
+</WRAP>
+  * Use prefixes to keep magnitudes practical (see <tabref prefix1> and <tabref prefix2>).
+  * Instead of writing zeroes for like in $0.000000004 ~\rm C $ is is easier to write $4 \rm ~nC $.
+  * For calculation it is often easier to write $4 ~\rm nC  = 4 \cdot 10^{-9} ~C$ or the notation ''\rm 4e-9 C''
+~~PAGEBREAK~~ ~~CLEARFIX~~
+==== Physical equations ====
+  * Physical equations allow a connection of physical quantities.
+  * There are two types of physical equations to distinguish:
+    * Quantity equations (in German: //Größengleichungen// )
+    * Normalized quantity equations (also called related quantity equations, in German //normierte Größengleichungen//)
+<WRAP group>
+<WRAP half column>
+<callout color="gray">
+==== Quantity Equations ====
+The vast majority of physical equations result in a physical unit that does not equal $1$.
+\\ \\
+Example: Force $F = m \cdot a$ with $[{\rm F}] = 1~\rm kg \cdot {{{\rm m}}\over{{\rm s}^2}}$
+\\ \\
+  * A unit check should always be performed for quantity equations
+  * Quantity equations should generally be preferred
+</callout>
+</WRAP>
+<WRAP half column>
+<callout color="gray">
+==== normalized Quantity Equations ====
+In normalized quantity equations, the measured value or calculated value of a quantity equation is divided by a reference value.
+This results in a dimensionless quantity relative to the reference value.
+Example: The efficiency $\eta = {{P_{\rm O}}\over{P_{\rm I}}}$ is given as quotient between the outgoing power $P_{\rm O}$ and the incoming power $P_{\rm I}$.
+As a reference the following values are often used:
+  * Nominal values (maximum permissible value in continuous operation) or
+  * Maximum values (maximum value achievable in the short term)
+For normalized quantity equations, the units should **always** cancel out.
+</callout>
+</WRAP>
+</WRAP>
+<callout title="Example for a quantity equation">
+Let a body with the mass $m = 100~{\rm kg}$ be given. The body is lifted by the height $s=2~{\rm m}$. \\
+What is the value of the needed work?
+\\ \\
+physical equation:
+<WRAP indent><WRAP indent>
+Work = Force $\cdot$ displacement
+\\ $W = F \cdot s \quad\quad\quad\;$ where $F=m \cdot g$
+\\ $W = m \cdot g \cdot s \quad\quad$ where $m=100~{\rm kg}$, $s=2~m$ and $g=9.81~{{{\rm m}}\over{{\rm s}^2}}$
+\\ $W = 100~kg \cdot 9.81 ~{{{\rm m}}\over{{\rm s}^2}} \cdot 2~{\rm m} $
+\\ $W = 100     \cdot 9.81 \cdot 2 \;\; \cdot \;\; {\rm kg} \cdot {{{\rm m}}\over{{\rm s}^2}}         \cdot {\rm m}$
+\\ $W = 1962 \quad\quad \cdot \quad\quad\;  \left( {\rm kg} \cdot {{{\rm m}}\over{{\rm s}^2}} \right) \cdot {\rm m} $
+\\ $W = 1962~{\rm Nm} = 1962~{\rm J} $
+</WRAP></WRAP>
+</callout>
+==== Letters for physical quantities ====
+<WRAP right 50%>
+<tabcaption tab03| greek letters >
+^ Uppercase letters  ^ Lowercase letters          ^ Name     ^ Application ^
+| $A$                | $\alpha$                   | Alpha    | angles, linear temperature coefficient                       |
+| $B$                | $\beta$                    | Beta     | angles, quadratic temperature coefficient, current gain      |
+| $\Gamma$           | $\gamma$                   | Gamma    | angles                                                       |
+| $\Delta$           | $\delta$                   | Delta    | small deviation, length of a air gap                         |
+| $E$                | $\epsilon$, $\varepsilon$  | Epsilon  | electrical field constant, permittivity                      |
+| $Z$                | $\zeta$                    | Zeta     | - (math function)                                            |
+| $H$                | $\eta$                     | Eta      | efficiency                                                   |
+| $\Theta$           | $\theta$, $\vartheta$      | Theta    | temperature in Kelvin                                        |
+| $I$                | $\iota$                    | Iota     | -                                                            |
+| $K$                | $\kappa$                   | Kappa    | specific conductivity                                        |
+| $\Lambda$          | $\lambda$                  | Lambda   | - (wavelength)                                               |
+| $M$                | $\mu$                      | Mu       | magnetic field constant, permeability                        |
+| $N$                | $\nu$                      | Nu       | -                                                            |
+| $\Xi$              | $\xi$                      | Xi       | -                                                            |
+| $O$                | $\omicron$                 | Omicron  | -                                                            |
+| $\Pi$              | $\pi$                      | Pi       | math. product operator, math. constant                       |
+| $R$                | $\rho$, $\varrho$          | Rho      | specific resistivity                                         |
+| $\Sigma$           | $\sigma$                   | Sigma    | math. sum operator, alternatively for specific conductivity  |
+| $T$                | $\tau$                     | Tau      | time constant                                                |
+| $\Upsilon$         | $\upsilon$                 | Upsilon  | -                                                            |
+| $\Phi$             | $\phi$, $\varphi$          | Phi      | magnetic flux, angle, potential                              |
+| $X$                | $\chi$                     | Chi      | -                                                            |
+| $\Psi$             | $\psi$                     | Psi      | linked magnetic flux                                         |
+| $\Omega$           | $\omega$                   | Omega    | unit of resistance, angular frequency                        |
+</tabcaption>
+</WRAP>
+Latin/Greek letters are reused across physics.
+In physics and electrical engineering, the letters for physical quantities are often close to the English term.
+Thus explains $C$ for //**__C__**apacity//, $Q$ for //**__Q__**uantity// and $\varepsilon_0$ for the //**__E__**lectical Field Constant//.
+But, maybe you already know that $C$ is used for the thermal capacity as well as for the electrical capacity.
+The Latin alphabet does not have enough letters to avoid conflicts for the scope of physics.
+For this reason, Greek letters are used for various physical quantities (see <tabref tab03>).
+Especially in electrical engineering, **upper/lower case letters** are used to distinguish between
+  * a constant (time-independent) quantity, \\ e.g. the period $T$
+  * or a time-dependent quantity, \\ e.g. the instantaneous voltage $u(t)$
+  * EE relies on case and context (e.g., $U$ vs. $u(t)$). Time-varying quantities often use lowercase, constants uppercase.
+~~PAGEBREAK~~ ~~CLEARFIX~~
+==== Notation & units ====
+The course consistently uses the following symbols, units, and typical values:
+<tabcaption notation | Course-wide notation and units>
+^ Symbol ^ Quantity                          ^ SI unit   ^ name of the unit  ^ Typical values  ^
+| $q$       | Electric charge                | $\rm C$   | Coulomb           | $10^{-19} ~\rm C$ (electron) to $\rm mC$              |
+| $I$       | Electric current               | $\rm A$   | Ampere            | $\rm \mu A$ (sensors) to $\rm kA$ (lightning)         |
+| $U$       | Voltage (potential difference)  | $\rm V$  | Volt              | $\rm \mu V$ (noise) to $\rm MV$ (transmission lines)  |
+| $\varphi$  | Electric potential            | $\rm V$   | Volt              | — |
+| $P$       | Power                          | $\rm W$   | Watt              | $\rm mW$ (electronics) to $\rm MW$ (machines)         |
+| $W$       | Energy                         | $\rm J$   | Joule             | $\rm µJ$ (capacitors) to $\rm MJ$ (batteries)         |
+| $R$       | Resistance                     | $\rm \Omega$  | Ohm           | $\rm mΩ$ to $\rm MΩ$                                  |
+| $G$       | Conductance                    | $\rm S$   | Siemens           | $\rm µS$ to $\rm S$                                   |
+| $\rho$    | Resistivity                    | $\rm \Omega \cdot m$      | — | $1.7 \cdot 10^{-8} ~\rm \Omega m$ (Cu)                |
+| $\sigma$  | Conductivity                   | $\rm S/m$                 | — | $5.8 \cdot 10^{7} ~\rm S/m$ (Cu)                      |
+| $C$       | Capacitance                    | $\rm F$    | Farad            | $\rm pF$ (ceramic) to $\rm F$ (supercaps)             |
+| $L$       | Inductance                     | $\rm H$    | Henry            | $\rm \mu H$ to $\rm H$                                |
+| $E$       | Electric field strength        | $\rm V/m$                 | — | $\rm 1 ~\rm V/m$ to $\rm MV/m$ (breakdown)            |
+| $D$       | Electric flux density          | $\rm C/m²$                | — | — |
+| $B$       | Magnetic flux density          | $\rm T$    | Tesla            | $\rm \mu T$ (Earth) to several $\rm T$ (MRI)          |
+| $H$       | Magnetic field strength        | $\rm A/m$                 | — | — |
+| $\Phi$    | Magnetic flux                  | $\rm Wb$   | Weber            | $\rm \mu Wb$ to $\rm mWb$                             |
+| $\theta$  | magnetic voltage (Magnetomotive force)                     | $\rm A \cdot turn$  | — | — |
+| $R$       | Reluctance                      | $\rm A/Wb$               | — | — |
+</tabcaption>
+===== Common pitfalls & misconceptions =====
+  * **Case matters:** $\rm M$ (mega, $10^6$) vs. $\rm m$ (milli, $10^{-3}$);
+  * **Micro symbol:** use $\rm \mu$ (or ''u'' only when typing constraints exist);
+  * **usage of prefixes** never stack prefixes (no “$\rm mµF$”).
+  * **Mixed units:** keep SI consistently; avoid mixing $\rm hours$/$\rm Wh$ inside SI derivations.
+  * **Units vs. variables:** don’t confuse $W$ (work) with $\rm W$ (Watt = unit of power $\rm P$ = work per second). \\ Don’t confuse $C$ (capacity = charge per voltage) with $\rm C$ (Coulomb = unit of charge $\rm Q$).
+  * **Units vs. prefixes:** don’t confuse $\rm mN$ (Millinewton) with $\rm Nm$ (Newton meter).
+  * **Normalized vs. quantity equations:** dimensionless ratios should cancel units; if not, something’s wrong.
+===== Exercises =====
+==== Quick checks ====
+#@TaskTitle_HTML@##@Lvl_HTML@#~~#@ee1_taskctr#~~.1  Unit check (quantity equation)
+#@TaskText_HTML@#
+Show that $P=U\cdot I$ has unit watt. (Better to be calulcated after reading Block02)
+#@ResultBegin_HTML~conv1~@#
+  - $[U]=\rm{V}=\rm{kg}\,\rm{m}^2\,\rm{s}^{-3}\,\rm{A}^{-1}$, $[I]=\rm{A}$.
+  - $[P]=[U][I]=\rm{kg}\,\rm{m}^2\,\rm{s}^{-3}=\rm{W}$.
+#@ResultEnd_HTML@#
+#@TaskEnd_HTML@#
+#@TaskTitle_HTML@##@Lvl_HTML@#~~#@ee1_taskctr#~~.2  Work from lifting (quantity equation)
+#@TaskText_HTML@#
+How much energy is needed to lift 100 kg for 2 meters?
+#@ResultBegin_HTML~quant1~@#
+  - $W=mgs$ with $m=100~\rm{kg},\,g=9.81~\rm{m/s^2},\,s=2~\rm{m}$
+  - $W=100\cdot9.81\cdot2~\rm{Nm}=1962~\rm{J}$
+#@ResultEnd_HTML@#
+#@TaskEnd_HTML@#
+#@TaskTitle_HTML@##@Lvl_HTML@#~~#@ee1_taskctr#~~.1  Conversion
+#@TaskText_HTML@#
+Convert $47~\rm{k\Omega}$ to $\rm{M\Omega}$ and $\Omega$.
+#@ResultBegin_HTML~conv2~@#
+$47~\rm{k\Omega}=0.047~\rm{M\Omega}=47{,}000~\Omega$.
+#@ResultEnd_HTML@#
+#@TaskEnd_HTML@#
+#@TaskTitle_HTML@##@Lvl_HTML@#~~#@ee1_taskctr#~~.2  Dimension
+#@TaskText_HTML@#
+Is $\eta=\dfrac{P_\rm{O}}{P_\rm{I}}$ dimensionless?
+#@ResultBegin_HTML~dim1~@#
+Yes. Units cancel ($\rm W/W$); normalized equation.
+#@ResultEnd_HTML@#
+#@TaskEnd_HTML@#
+#@TaskTitle_HTML@##@Lvl_HTML@#~~#@ee1_taskctr#~~.3  Conversion
+#@TaskText_HTML@#
+Which is larger: $5~\rm{mA}$ or $4500~\rm{\mu A}$?
+#@ResultBegin_HTML~conv3~@#
+$5~\rm{mA}=5000~\rm{\mu A}$, so $5~\rm{mA}$ is larger.
+#@ResultEnd_HTML@#
+#@TaskEnd_HTML@#
+#@TaskTitle_HTML@##@Lvl_HTML@#~~#@ee1_taskctr#~~.4  Conversion
+#@TaskText_HTML@#
+True/False: $1~\rm{V}=1~\rm{Nm/As}$.
+#@ResultBegin_HTML~conv4~@#
+True (from $W=U \cdot Q$).
+#@ResultEnd_HTML@#
+#@TaskEnd_HTML@#
+==== Longer exercises ====
+{{tagtopic>chapter1_1&nodate&nouser&noheader&nofooter&order=custom}}
+===== Embedded resources =====
+\\ \\
+<WRAP column half>
+A nice 10-minute intro into some of the main topics of this chapter
+{{youtube>IOb3-JZPY0Y}}
+</WRAP>
+<WRAP column half>
+Short presentation of the SI units
+{{youtube>hQpQ0hxVNTg}}
+</WRAP>
+\\ \\
+<WRAP column half>
+Orders of magnitude and why prefixes matter.
+{{youtube>jjvIy04PwYI}}
+</WRAP>
+\\ \\
+~~PAGEBREAK~~ ~~CLEARFIX~~
+===== Mini-assignment / homework (optional) =====
+List 10 everyday EE-relevant quantities (e.g., USB current, phone battery energy, LED forward voltage).
+For each:
+  * write as value × unit with an appropriate prefix,
+  * convert to base SI units, and
+  * if a formula applies (e.g., $P=U\cdot I$), do a unit check.