@?electricity

See Also [[Physics - Internal Resistance]]S [[Physics - Voltage and Potential Difference]]S Flashcards If the resistance of $R_1$ is twice that of $R_2$, how much more of the total potential difference does $R_1$ get?? Twice as much. What is the potential divider equation?? $$ V_{\text{out}} = V_{\text{in}} \times \frac{R_1}{R_1 + R_2} $$ Backlinks [[Physics - Syllabus]]S Metadata date: 2021-05-05 15:53 tags: - '@?physics' - '@?

See Also [[Physics - Resistance and Ohm's Law]]S [[Physics - Voltage and Potential Difference]]S Flashcards If $E$ is the E.M.F. of a battery and $V$ is the terminal voltage, what is the formula for “lost volts”?? $$ Ir = E - IR $$ Why are there “lost volts” in a battery?? Because the battery has some internal resistance. Why do the lights on old-fashioned cars blink out when you start the engine?

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.

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?

See also: [[Physics - Circuits]]S [[Physics - Voltage and Potential Difference]]S What is electric current?? The rate of flow of charged paticles. What symbol is used to represent current?? $$ I $$ What are some examples of charged particles?? Electrons, $e^{-}$ Positrons, $e^{+}$ Protons, $p$ Ions, $Na^{+}$, $Cu^{++}$ Why is $I$ used to represent current?? Because it comes from the french “Intensity of Current”. What are the units for current?

Energy What is power?? Power is the rate at which work is done. What is the symbol formula for power?? $$ P = \frac{W}{t} $$ If velocity is the rate of change of displacement, work done is?? The rate of change of energy. What is the unit of power?? $$ \text{watt}, W $$ What is the equation for power in terms of velocity?? $$ P = Fv $$ How is efficiency calculated?? $$ \frac{\text{useful output energy}}{\text{total input energy}} \times 100% $$