Egee 101 practice Questions With Complete Solutions

Through a combination of fertility rate and decreased poverty levels, a population's energy use is growing exponentially 1% per year. How many years until the energy use doubles? - ANS 69.3 years What energy growth rate per year would increase world energy use by 400% 92 doubling periods) in 80 years? - ANS 1.7% per year What has more kinetic energy? - ANS A car moving at 120 mph across the bonneville salt flats Which series goes from least energetic to most? - ANS Radio infrared ultraviolet x-rays What has more potential energy? - ANS A cubic mile of water (a lake) behind a 300 ft tall dam Which has more chemical energy? - ANS An oil tanker moored at a terminal Which has more nuclear energy? - ANS An atomic bomb in a silo in North Dakota What transformation occurs in a computer? - ANS Electrical to light/sound The hot coffee heats the mug which heats my hands which are holding the mug, what method of heat transfer is it? - ANS Conduction What transformation occurs in the sun? - ANS Nuclear to radiation What transformation occurs in a lawn mower? - ANS Chemical to kinetic/ mechanical A power plant consumes 100 MJ of energy, of which only 24 MJ are wasted heat. What is the efficiency? - ANS 0.76 a power plant converts 100 KJ of coal into 30 KJ of electrical energy. What is the efficiency? - ANS 30% Your home converts 30 KJ of electrical energy into 15 KJ of useful energy (heat,electric) and 15 KJ of wasted energy. What is your home's efficiency? - ANS 50% It took 100 KJ of coal to produce the 15 KJ of useful energy in your home. What is the total efficiency? - ANS 15% Penn state natural gas plant produces 7 MW of power. If it runs at 70% efficiency and has 7 MW Power Out, what is the rate of energy input? - ANS 10 MW Penn state natural gas plant produces 7 MW of power. What if Penn State could successfully reuse 1/3rd of the remaining rejected heat... what is the new process efficiency? - ANS 80% If Penn states power generation is 70% efficient and campus efficiency (dorms, labs, lecture halls) is raised from 50% to 90%, what is the new process efficiency? - ANS 63% Kevin wants to use less fossil fuel by purchasing an electric vehicle. EV's are currently about 50% efficient. The power in Kevin's neighborhood comes from a coal-fired power plant. When Kevin plugs his EV in at night, what is powering his car? - ANS Coal Kevin wants to use less fossil fuel by purchasing an electric vehicle. EV's are currently about 50% efficient. The grid is about 20% efficient and Kevin's EV is about 50% efficient. What is the total efficiency of this process? - ANS 10% Kevin wants to use less fodder fuel by purchasing an electric vehicle. EV's are currently about 50% efficient. Gasoline engines are about 25% efficient. What is better for Kevin's wallet and for the environment? - ANS 25% overall efficient use of gasoline Kevin lives next to a coal fired power plant. He wants to be greener, so he buys an electric vehicle, which he charges with his home's electricity. Is Kevin helping the environment? - ANS No, the process efficiency and carbonized power grid make Kevin's EV dirtier than an IC (internal combustion vehicle) In 2019 the U.S. used 100.2 quads of energy out of which 67.5 quads were rejected energy. What is the US energy efficiency - ANS 32% At $52 /ton, what is the price of coal per MMBTU? - ANS $2 At $260/ ton, what is the price of coal per MMBTU - ANS $10 At $58/bbl, what is the price of oil per MMBTU? - ANS $10 At $3/MCF, what is the price of natural gas per MMBTU? - ANS $3 What is the weight percent of fixed carbon if moisture = 3 wt. %, volatile matter = 37wt. %, and ash 10 at. %? - ANS 50% What is the ash yield if the weight of the ash remaining is 25 grams and weight of the pre-combustion sample is 100 grams? - ANS 25% How many ranks of coal are there? - ANS 4 Which coal rank has the lowest carbon content? - ANS Lignite Where does coal come from? - ANS Swamps buried millions of years ago Which coal rank has the highest heating value? - ANS anthracite There are 100 tons of coal and 10 consumers who each want 10 tons. If a consumer leaves the market, what happens to the price of coal? - ANS The price of coal goes down There are 100 tons of coal and 10 consumers who each want 10 tons. If an additional consumer enters the market and wants 10 tons of coal, what happens to the price of coal? - ANS The price of coal goes up Approximately how many people do you think die in coal mines each year in the US? - ANS Tens Which is not an underground mining method? - ANS High wall mining Which is not a surface mining method? - ANS Slope mining How does oil reside in the ground? - ANS In porous rocks, like water in a sponge Which sector uses the most of petroleum? - ANS transportation How much of the transportation sector is fueled by petroleum? - ANS 92% How long will oil last? - ANS 50 years Do you think there is more oil to be found? - ANS No, we've pretty much found it all Which is a property of crude oil? - ANS Very low sulphur Tar sands require additional processes to separate bitumen and sand before the refining process. - ANS True Which are the properties of good crude oil - ANS Low viscosity, low density