@?school

Facebook had a big book of everyone’s faces – scary. How has our connected, online world enabled us to publish and distribute personal information? Do you post personal information about yourself online? Do you post persona information about other people online? Is this ethical? How many people in different countries use social networking sites such as Facebook or Twitter? What are some of the negative aspects of social media sites? Negative aspects: Internet trolling Cyberbullying Anonymous blogs Hate sites Should all information be easily and freely accessible to all online?

What type of conductor are thermistors?? Semiconductors. What type of conductor are LDRs?? Semiconductors. How do thermistors and LDRs work?? They have a number densitry that changes in response to environmental effects. What does the resistance-temperature graph look like for a typical thermistor?? For a typical thermistor, what does a low temperature mean?? A high resistance. What does NTC stand for?? Negative Temperature Coffecient. What does a Negative Temperature Coefficient mean?? A low temperature will have a high resistance.

Flashcards What is the symbol for wavelength?? $$ \lambda $$ What is the symbol for the period of oscillation in a wave?? $$ T $$ What is the symbol for wave speed?? $$ v $$ What is the frequnecy of a wave?? The number of wavelengths passing through a given point per unit time. What is the period of oscillation of a wave?? The time taken for a wave to move one whole wavelength past a given point.

See Also [[Stats - Statistical Distributions]]S [[Stats - Probability]]S [[Maths - Combinations]]?? Flashcards What $ \left(\begin{matrix} n \ r \end{matrix}\right) $ could you write for the number of ways you can pick $3$ students from a class of $28$?? $$ \left(\begin{matrix} 28 \\ 3 \end{matrix}\right) $$ What $ \left(\begin{matrix} n \ r \end{matrix}\right) $ could you write for the number of ways you could pick $2$ left-handed people from a total of $3$ people?

What three things does the resistivity depend on?? The material of the wire. The length of the wire. The cross-sectional area of the wire. If you double the length of a wire, what happens to the resistance?? It also doubles. What’s the difference between resistivity and resitance?? Resistivity is the property of a material whereas resistance is just a measurement of a component. How would you write that the resistance $R$ is directly proportional to its length $L$?

See Also [[Stats - Binomial Distribution]]S [[Stats - Probability]]S Flashcards What is a random variable?? A variable whose value depends on the outcome of a random event. What is the notation for a random variable?? Capital letters, $X$. What is the notation for the random variable $X$ taking a particular value $x$?? $$ P(X = x) $$ Can you explain $P(X = x) The probability that the outcome of the random variable $X$ was the specific outcome $x$.

What is Ohm’s Law?? The current through an ohmic conductor is proportional to the potential difference across it when at a constant temperature. What is the symbol formula for resistance?? $$ R = \frac{V}{I} $$ What is the word formula for resistance?? $$ \text{resistance} = \frac{potential difference}{current} $$ What is the formula for potential difference $V$ in terms of resistance $R$ and current $I$?? $$ V = IR $$ What is the formula for current $I$ in terms of resistance $R$ and potential difference $V$?

2021-01-18 What does “potential energy” mean?? The potential to do work. How does a stretched elastic band have the potential to do work?? When it is released it will move. What is potential difference?? The energy transfered per unit charge from electrical energy to another form of energy. When used to measure a component, what does potential difference measure?? The difference in energy in the charge carriers before and after going through the component. What does EMF stand for?

What is the formula for the vertical component of a momentum $p$?? $$ p\sin\theta $$ What is the formula for the horizontal component of a momentum $p$?? $$ p\cos\theta $$ If an object with mass $m_1$ is travelling in a straight line with velocity $v_1$, what is its momentum?? $$ m_1v_1 $$ If an object with mass $m_1$ is travelling at an angle $\theta_1$ to the $x$ direction with velocity $v_2$, what is its momentum?? $$ m_1v_1\cos\theta_1 $$

What two forms do you give answers to probability questions?? Decimals Fractions What does $P(\text{experiment})$ mean?? The probability of experiment. In terms of probability, what is an experiment?? A repeatable process that gives rise to a number of outcomes. In terms of probability, what is an event?? A set of one or more outcomes. What is sample space?? The set of all possible outcomes. 2021-01-21 What does it mean for two events to be mutually exclusive?

What regular expression is this?? $$ ab $$ What regular expression is this?? $$ a|b $$ What regular expression is this?? $$ a+ $$ What regular expression is this?? $$ a* $$ Visualise the finite state machine for $ab$?? Visualise the finite state machine for $a|b$?? Visualise the finite state machine for $a+$?? Visualise the finite state machine for $a*$?? What is the precedence for regular expressions?? () * + ? | Backlinks [[Computing - Syllabus]]S [[Computing - Regular Languages]]S Metadata date: 2021-01-11 08:41 tags: - '@?

Questions for Teacher If there’s no potential difference in a wire, what happens to the electrons?? They will drift randomly. What happens to the randomly drifting electrons in a wire when a potential difference is applied?? They start to drift in the same direction. What is meant by electron drift velocity?? The average displacement of the electrons along the a wire per second. Why do electrons move slowly through a metal?? Because the electrons are colliding with the lattice of atoms.