# Practice Problems

Students - please put in two questions for the review and work out entire example.

Put your answers in boxes by putting a space before it.


Make sure to include all equations and units. Make sure to tag your question with --~~~~

If possible make these questions multiple choice.

Thank you.

According to the graph above, how many dollars were saved in the 5th year of energy conservation? a. 100 b. 300 c. 450

Answer: b. 300 dollars.


• According to the graph above, during what year did the biggest drop in money saved occur?

a. years 3-5 b. years 2-4 c. years 7-8

Answer: c. years 7-8


## Nuclear Energy

• How much energy, in MeV, does a fission of a uranium atom let off?

A. 150 MeV B. 10,000 MeV C. 500 MeV D. 200 MeV

The correct answer is D.


• The following diagram is an example of what?

A. Nuclear Bomb B.Electrons C.Fission Reaction D.photons

The Correct answer is C. Fission Reaction.

• What is the difference between fusion and fission?
Answer: Fission splits a big element into fragments, releasing
energy in the process.  Fusion joins two smaller elements, forming a
bigger element, and releasing energy in the process.


• If you have 34 protons and 23 neutrons, what is the nuclear number?
Answer: 57

• A chain reaction of fission results in what?
a)nothing b)water c)nuclear bomb d)all of the above e)none of the above

The answer is C

• True or False: by slowing fission down you can possibly stop it?
  the answer is False, you can slow fission down but you can never stop it.


• Out of the types of radiation that we talked about in class put the three types in order of least engery to most energy.

• What type of radiation can go through brick walls and can partly pass through lead?

A. Alpha B. Beta C. Gamma

The answer is C Gamma Radiation

• What does EB stand for in the equation: EB=Δmc2?

A. Blinding Energy B. Broken Energy C. Binding Electrons D. Binding Energy

The answer is D. Binding Energy

• Why doesn't a nuclear reaction inside a nuclear energy plant get out of control when using Uranium 235?

A. Fuel Rods B. Water C. Control Rods D. Turbine

The correct answer in C.

• Fill in the blank:

Kelly is standing 10 feet in front of a brick wall and is exposed to the 3 types of radiation alpha, beta and gamma. ________ goes through Kelly's body and into the brick wall, _______ only goes to Kelly's hand and stops, and _______ goes through Kelly's hand but doesn't go through the brick wall.

  Answer: gamma, alpha, beta

• What are the components of this equation A= Z+N?

a. A= atomic number, Z= electrons and N= neutrons

b. A= nuclean number, Z= protons and N= neutrons

c. A= atoms, Z= protons and N= nuclear

• Between the three types of different radiation, which of the three would go thru a brick wall?
Gamma Rays- high energy photon

• How can you protect yourself from the three types of radiation?

a. time b. distance c. shielding d. all the above

• One atomic unit equals_____?

a. 1.26 x10^-25 b. 1.66 x10^-27 c. 2.16 x10^-27 d. 1.46 x10^-7

B. is correct.


### Natural Uranium

1. How much of natural uranium is used for energy?

less than 1% is U235 at used for fission


2. What type of natural uranium is considered Fission? A. U238 B. U236 C. U235

 C. U235


### DU

1. True or False: Natural Uranium is safer than Depleted Uranium.

False; Depleted uranium is safer than natural uranium.



2.Natural uranium is made up of two different types, what are they and which one is used for energy and which is a waste product?

 U235- used for energy
U238- waste product


3.What are the two main uses for U238?

 Uses- armor & munitions



4. True of False: Depleted Uranium is still being used today.

Answer: True


5. Why is Uranium 238 such a high profit substance for companies such as Aeroset/Honeywell?

A. It is a great fuel source
B. It is an effective armor and weapon
C. It is very easily obtained and sometimes is obtained at no cost.
D. Both B and C

Answer: D is the correct answer. Uranium 238 is not a great fuel source but companies like Aeroset/Honeywell can make alot of money from selling armor and ammunition to the goverment. Not only that but they can obtain it from such entities who would give it away rather than paying to dispose of it properly.


## Electric Fields

• What is the equation for electric fields?
E=Fe/q [N/C]

• What is the q equal to on the equation for electric fields?

a.force b.charge c. distance

 charge

• What is the distance between charges if the Electrical Field (E) is equal to 4 [N/c], the constant (k) is equal to 1, and the total charges in the system is 6?

a. 2m b. 1.22m c. 4m d. 10m

The correct answer is b.) distance = 1.22m.
E = k|Q|/ r^2
4 = 1 (6) / r^2
4 = 6/ r^2
4 x r^2 = 6
r^2 = 6/4
r = 1.22m

Note k is not 1 in reality.


## Magnetic Fields

   The magnitude of the electromagnetic force around a loop is equal to the rate change of
the magnetic flux through the loop.

• What are the two ways to change the rate of change of the magnetic flux?
    Move the loop or move the magnet.

• The law that states, the magnitude of induced emf around a loop is equal to the rate of change of the magnetic flux through the loop, is known as what law?

A.Fourier's Law B.Faraday's Law C.Newton's Law D.Law of Thermodynamics

The correct answer is B. Faraday's Law.

• Will the north pole of a magnet attract the south pole or the north pole of another magnet?
The answer is the south pole of another magnet. Remember, opposites attract.

• What is the formula for a Magnetic Force?
F=|Q|VperpendicularB


• The magnetic force Fm on a charge q moving with a velocity v in a magnetic field B is given by Fm = q(v x B). Which of the following statements are always true?

a) Fm is always perpendicular to v. (b) v is always perpendicular to B. (c) Fm is always perpendicular to B.

With Fm = q(v x B), Fm is always perpendicular to v

Multicrystaline Silicon, Crystal Silicon, and Amorphaos Silicon are 3 types of what?
a) solar cells b) glass panes c) metal d) non of the above

The answer is a.


• Which of the following is wrong?

a. + attracts - b. + repels + c. + repels - d. - repels -

  the answer is c


• What does emf stand for?

A. Electromagnetic friction B. Electro magnitude force C. Electromagnetic force D. Electric magnetic friction

Answer is C. Electromagnetic force

• _________________ states that the magnitude of the induced electromagnetic force (EMF) around the loop is equal to the rate of change of the magnetic flux through the loop.

a. Fuller's Law b. Huygen's Principle c. Faraday's Law d. Farrier's Law

Correct answer is C. Faraday's Law

• Does Faraday's law state that the magnitude of the electromagnetic force around the loop is not equal to the rate of change of the magnetic flux through the loop?

a. True

B. False

  Correct answer is B. False because it is equal.

• If North and South ends are pointing towards one another what is the outcome?
They will pull together and connect.


• If you want to change the magnetic flux through the loop. which one is not the right way to do?
 A. Change the size of loop
B. move the loop
C. move the magnetic
D.put something between them


## Wave review

1. What is the definition of a wave?
   Any pattern with and indentifable periodicity in space and time. No matter is transferred but energy is.

1. What is the highest point of a wave?

A. trough B. crest C. amplitude

B. crest


• When waves are tightly put together this means the waves have a _________?

A) High Velocity B) Low Frequency C) High Amplitude D) High Frequency

## Solar photovoltaic cells

• Out of crystal silicon, multicrystal silicon, and amorphous silicon, which has the highes efficiency as well as the highest cost?
    Crystal Silcon

• Which of the following solar cells work with a pn junction?

A.Crystal silicon and Amphorus silicon B.Multicrystallie silicon and Amphorus silicon C.Crystal silicon and Multicrystalline silicon D.All the above

 Answer: C Crystal silicon and Multicrystalline silicon

• When a light photon is emitted through a pn junction it creates electricity. What happens when electricity is pushed through a pn junction? What is this also called?
When electricity is pushed through a pn junction it creates light. It is also a LED or light emmitting diode.

• What does the n stand for in the pn junction
a) Non-silicon b) negative c) photons d) none of the above


• Out of the three types of solar cells which is the cheapest to purchase?

A. Crystal Silicon B. Amorphus Silicon C. Multicrystalline silicon

 Amorphous Silicon

• Out of the three types of silicon solar cells which is circular shaped?
Crystal Silicon


• What are the economical benefits of solar research and energy efficiency research as it relates to the work force.
   The amount of longterm jobs related to these fields way outnumber other energy related jobs.

• True or False: Northwestern Pennsylvania is one of the best places in the United States for solar power use.
False


Of the following, which is not an advantage of Amorphus Silicon? A. high absorption B. it is cheaper than the glass, plastic, or metal you deposit on it C. it degrades when light hits it D. it is an established technology

the answer is C

• Of the three types of solar cells which one of them has a pin structure rather than a pn structure?
  amorphous silicon

• What does it mean to live "off-grid"?
  To live off the grid means that you supply your own electricity.  Usually with the use of solar cells or small windmills.