EGEE 101 FINAL EXAM Questions
C
21 million Joules of chemical energy are supplied to a boiler in a power plant. 5 x 10^6 Joules of energy are lost through unburned fuel. The boiler radiates 1.5 million Joules to the atmosphere. What is the efficiency of the boiler in percentage? (2 points) A) 69.0% B) 6.90% C) 0.690% D) 27.5%
D
An automobile engine gives 30,000 BTUs of mechanical energy from 100,000 BTUs of fuel. The transmission, axles and tires deliver 27,000 BTUs of mechanical energy to the highway, moving the car forward. What is the overall efficiency of this vehicle? A) 27,000 B) 30% C) 90% D) 27%
A
How can passive solar energy be utilized (northern hemisphere)? A) Put more windows on the sunny side of the house (south). B) Plant deciduous trees on the north side of the house. C) Put larger windows on the north side. D) Both B & C
D
If the energy input of a system is 200 calories and its useful output is 138 calories, what is the efficiency of the system? A) 0.78 B) 0.7931 C) 0.18 D) 0.69
A
If the world demand for energy is growing at the rate of 7% per year, when would we expect the energy demand to be twice today's? A) 10 years B) 6 years C) 7 years D) 20 years
c
In a light bulb, the useful energy output is in the form of __________ energy. A) Mechanical B) Chemical C) Radiation D) Thermal / heat
d
In the US, most of the electricity is generated from A) Wind B) Fuel oil C) Hydroelectric D) Coal
D
In the US, we rely less on energy from ____________ than in earlier decades? A) Nuclear B) Natural gas C) Petroleum D) Wood
b
In the process of refining petroleum, the useful energy output is in the form of __________ energy. A) Mechanical B) Chemical C) Radiation D) Thermal / heat
B
The quantity of an energy source that is known to exist and that can be economically recovered is called? A) Resource B) Reserve C) Supply D) Asset
A
The useful output from a heat engine is 481 joules. The energy that is wasted is 2214 J. What is the efficiency of the engine? A) 0.1784 B) 0.217 C) 21.7 D) 4.6
A
What is doubling time? A) Time during which the initial quantity increases by a factor of two B) Time it takes for a radioactive sample to decrease to half the original mass C) A measure of radioactive decay D) Radioactivity
A
Where do you think the heating degree days would be the highest? A) North Pole B) Equator C) Houston D) State College
A
Which US economic sector uses the most petroleum in the US? A) Transportation B) Industrial C) Residential D) Commercial
C
Which energy conversion device typically has the highest energy efficiency? A) Automobile engine B) Home oil furnace C) Electric motor D) Steam boiler
d
Which energy source is used most for US home heating? A) Electricity B) Coal C) Oil D) Natural Gas
A
Which of the following is not a unit of energy? A) Watts B) BTUs C) Joules D) Calories
A
Which of the following is the largest energy consumer at home? A) Space heating B) Air conditioning C) Water heating D) Lighting & appliances
d
Which of these produce the maximum heat? A) CFL B) Incandescent bulbs C) Fluorescent bulbs D) Halogen bulbs
B
Which sector of the US economy uses energy the least efficiently? A) Industry and manufacturing B) Transportation C) Commercial D) Residential
D
Worldwide, we expect the use of which energy resource to decrease over the next 20 years? A) Nuclear B) Coal C) Hydroelectric D) None of the above
A
A watt is a unit of? A) Power B) Energy C) Lighting D) Mass
D
Energy demand is a/an A) Linear function - it goes up steadily over time B) Logarithmic function - the longer it goes, the less rapidly it grows C) Sine function - it goes up and down predictably, in cycles D) Exponential function - the longer it goes, the more rapidly it grows
B
Three energy conversion processes take place in succession. The first has an efficiency of 51%, the second is 50% efficient, and the third 5%. What is the efficiency of the entire process? A) 0.37 B) 0.0128 C) 0.0255 D) 1.11