Download Physics 109 Quiz 5 April 4, 2014

Physics 109
Quiz 5
April 4, 2014
1. Why do clothes often cling together after tumbling in a clothes dryer?
(A) There is less water in the clothes
(B) Electrons get rubbed off some items onto others
(C) Protons get rubbed off some items onto others
(D) The resistance to flow of electricity increases as the clothes dry
2. If an electron and a proton both experience the same electric force,
(A) the proton will have greater acceleration.
(B) the electron will have greater acceleration.
(C) their accelerations will have the same magnitude.
(D) neither will accelerate.
3. Coulomb’s law says the force between two charged points is
(A) proportional to the charges
(B) inversely proportional to the distance between the points squared
(C) related by the proportionality constant 8.988 x 109 N m2 /C2
(D) A, B and C
4. Who originally named electric charges as positive and negative?
(A) Andre Marie Ampere
(B) Michael Faraday
(C) Benjamin Franklin
(D) Charles Augustin de Coulomb
5. A positive point charge is placed at a point in space that has an electric field pointing
due north. What direction will the point charge move.
(A) due north
(B) due south
(C) due east
(D) due west
6. Good electrical conductors are usually good thermal conductors because
(A) neither type of object has a high specific heat.
(B) both types of objects have low density.
(C) of pure coincidence.
(D) electrons are responsible for thermal and electric conduction.
7. In the dark, the photo-conductors used in most xerographic copiers are
(A) super-conductors.
(B) insulators.
(C) semi-conductors.
(D) conductors.
8. A 12 volt battery is connected across a 36Ω resistor. The current through the resistor
is:
(A) 3 Amperes
(B) 0.3 Amperes
(C) 0.33 Ampere
(D) 0.033 Ampere
9. An electrical appliance has a power rating of 600 Watts when connected to a 120 volt
electrical outlet. What is the resistance of the appliance?
(A) 24 Ω
(B) 12 Ω
(C) 5 Ω
(D) 0.48 Ω
10. You are working with a magnet and it breaks in half. You then end up with
(A) Two north poles only
(B) Two magnets, each with a south and a north pole.
(C) One north and one south pole
(D) Two south poles only
11. Electricity and magnetism are different because
(A) Electrical forces decrease with increasing separation.
(B) Only magnetism has to do with electrons.
(C) There are no electric monopoles.
(D) There are no magnetic monopoles.
12. The source of all magnetism is
(A) ferromagnetic materials
(B) tiny domains of aligned atoms
(C) tiny pieces of iron
(D) moving electric charges
13. A magnetic field points due south and parallel to the surface of the earth. A positive
charge is moving due east parallel to the earth’s surface. What is the direction of the
magnetic force on the positive charge
(A) up
(B) down
(C) south
(D) north
14. A straight wire with a length of 0.2 meter has a current of 10 amperes flowing through
it in a region where there is a magnetic field of 2 Tesla. The field is perpendicular to
the wire. The magnitude of the force on the wire is:
(A) 0.2 Newtons
(B) 0.4 Newtons
(C) 2 Newtons
(D) 4 Newtons
15. Faraday’s law says
(A) current times resistance is equal to voltage
(B) a changing magnetic field produces an induced voltage
(C) there are no magnetic mono-poles
(D) a changing electric field produces an induced magnetic field
16. An electrical generator
(A) is normally used to create DC power
(B) generates electrical current by rotating a coil in an magnetic field
(C) use a magnetic field created by magnetic mono-poles
(D) can not make AC power
17. The principal advantage of sending electric power across country on very high voltage
transmission lines is that
(A) they carry less energy per charge than low voltage transmission lines.
(B) electric power lost in the wires is greatly reduced.
(C) these transmission lines are less likely to get in the way than low voltage transmission lineswhich are much closer to the ground.
(D) they carry much more current than low voltage transmission lines.
18. James Maxwell showed
(A) a changing magnetic field produces an electric potential
(B) light is an electromagnetic wave
(C) momentum is based on translational symmetry
(D) that magnetic mono-poles could not exist