Intro & Thermodynamic Limits Flashcards
What are the units of energy and power?
Energy- Joules
Power - Watts
About how much power does a large nuclear power station produce?
Around 1 GW of power
What was the approximate energy consumption in the UK in 2012?
8*10^18 J
About how much energy does a nuclear power station produce per year?
3.15*10^16 J
Approximately how much electricity does a UK person require?
4kW
About how much energy and power did the world consume in 2012?
5.6*10^20 J (17.7 TW)
Name 9 sources of electrical power.
- Coal
- Oil
- Gas
- Nuclear
- Solar
- Fusion
- Hydro
- Biofuel
- Wind
How do AC power stations generate emf?
- Spinning magnets past loops of wire
- Induces emf drives current
What is the equation for the efficiency of an idealised heat engine?
n = Work done/heat in = (Qin-Qout)/Qin
What are the 4 steps in the carnot cycle?
- Adiabatic expansion
- Isothermal compression
- Adiabatic compression
- Isothermal expansion
What are the characteristics of adiabatic expansion?
- Temp decreases
- Work greater than zero
- Heat transferred = 0
What are the characteristics of isothermal compression?
- Temp the same
- Work less than zero
- Heat out = Q(L) <0
What are the characteristics of adiabatic compression?
- Temp increases
- Heat transferred = 0
- Work done less than zero
What are the characteristics of isothermal expansion?
- Temp the same
- Work > 0
- Heat in = Q(H) > 0
What is the equation for Carnot efficiency of an engine?
n = 1 - T(out)/T(in)
