Exam 2 Flashcards | ENGR31230

"Formula: Ohm's Law"

"$V = IR$

"Formula: Electric Power (DC)"

"$P = VI$

"Formula: Transmission Line Power Loss"

"$P_{loss} = I^2 R$. This shows that power loss is proportional to the square of the current."

"Formula: Specific Heat Equation"

"$Q = mc\Delta T$

"Formula: Heat Loss Rate"

"$P = U\Delta T$

"Formula: Energy from Power and Time"

"$E = P \times t$. Energy equals Power multiplied by Time."

"Formula: Solar Energy Generation"

"$E = P{peak} \times t \times lf$

"Formula: Total Energy in a Battery"

"$E{total} = m \times ed$

"Definition: Watt (W)"

"The SI unit of power

"Definition: Kilowatt-hour (kWh)"

"A unit of energy equal to 1

"Definition: Specific Heat Capacity ($c$)"

"The amount of heat energy required to raise the temperature of one unit of mass of a substance by one degree Celsius."

"Definition: Energy Density"

"The amount of energy stored in a given system or region of space per unit mass or volume."

"Definition: Load Factor"

"The ratio of actual energy output over a period of time to the maximum possible output if operating at full capacity."

"Definition: Efficiency"

"The ratio of useful power output to total power input

"Concept: High Voltage Transmission"

"Increasing voltage allows power to be transmitted with lower current

"Concept: Voltage Drop"

"The decrease in electric potential along the path of a current flowing in a circuit

"Concept: Relationship between Voltage and Current (Constant Power)"

"For a constant amount of power ($P=VI$)

"Concept: Useful Power Calculation"

"To find useful power

"Calculation: Time to Heat"

"Time ($t$) is calculated by dividing the Total Energy required ($Q$) by the Power ($P$) of the heater: $t = Q/P$."

"Impact of doubling voltage on transmission loss"

"Doubling the voltage halves the current.

"Unit Conversion: kW to W"

"1 kW = 1000W"

"Unit Conversion: kJ to J"

"1 kJ = 1000J"

"Trivia: Specific Heat of Water"

"Water has a very high specific heat ($4.184 \text{ J/g}^\circ\text{C}$)

"Trivia: Joule vs. Watt"

"A Joule is a unit of energy (an amount), while a Watt is a unit of power (a rate of flow). Watts are Joules per second."

"Mnemonic: Power Loss"

"Twinkle Twinkle Little Star, Power equals I squared R." (Helps remember Ploss=I2R)