Physics 1320 Exam 4 TxState. Mount
True or False. A conductor differs from an insulator in that a conductor has more electrons than protons
False
True or False. A conductor differs from an insulator in that a conductor has more energy than an insulator
False
True or False. Current is the primary cause of voltage
False
True or False. Resistance flows through an open circuit
False
True or False. Voltage flows through a circuit
False
True or False. Voltage flows through an open or closed circuit
False
True or False. current causes voltage
False
True or false. Resistance is established across a circuit.
False
To say that an object is electrically polarized is to say
Its charges have been rearranged
When two lamps are connected in parallel to a battery, the electrical resistance that the battery senses is more or less than the resistance of either lamp? or neither?
Less than the resistance of either lamp
Rub electrons from your hair with a comb and the comb becomes
Negatively charged
Which pole of a compass needle points to a south pole of a magnet?
North pole
Charge carries in a metal are electrons rather than protons because electrons are
loosely bound
The electrical force between charges depends only on the charges
magnitude and separation distance
The source of all magnetism is
moving electric charge
A negatively charge rod is brought near a metal can that rests on a wood table. you touch the opposite side of the can momentarily with your finger. The can is then
positively charged
When the distance between two charges is halved, the electrical force between the charges
quadruples
Two uncharged metal spheres, #1 and #2, are mounted on insulating support rods. A third metal sphere, carrying a positive charge is then placed near 2. Now a copper wire is momentarily connected between 1 and 2 and then removed. Finally, sphere 3 is removed. In the final state what are the charges of sphere 1 and 2
sphere 1 carries a positive charge and 2 carries a negative charge
When a transparency sheet is rubbed with a tissue and the transparency and tissue are then held at rest a short distance apart
the two object exert electric forces on each other, because electrons are rubbed off of one and onto the other
When a car is struck by lightning, the resulting electric field inside the car is
zero
If you use 10J of work to push a coulomb of charge into an electric field, its voltage with respect to its starting position is
10V
The current through a 10 ohm resistor connected to a 120 V power supply is
12 A
When a battery does 24J of work on 10C of charge the voltage it supplies is
2.4V
The electric power of a lamp that carries 2A at 120V is
240
A 8 ohm resistor and a 6 ohm resistor and a 24 ohm resistor are connected together. What is the minimum resistance that can be produced using all three resistors?
3 ohms
A coulomb of charge that passes through a 6V battery is given
6 J
two charges separated by one meter exert 1N force on each other. If the charges are pushed to 0.25m separation, the force on each charge will be
6N
A 4 ohm resistor, an 8 ohm resistor, and a 24 ohm resistor are connected together. what is the maximum resistance that can be produced using all three resistors?
86 Ohms
Suppose that the electric force between two objects is 2 N and that you then have the distance between the objects
8N
An electron and a proton A. attract each other B. repel each other C. neither attract nor repel each other
A. attract each other
To say that electric charge is conserved is to say that electric charge
Can neither be created nor destroyed
Two charged particles attract each other with a force F. If the charges of both particles are doubled, and the distance between them is also doubled then the force of attraction will be
F
True or False. A conductor differs from an insulator in that a conductor has More protons than electrons
False
True or False. A conductor differs from an insulator in that a conductor has faster moving molecules
False
The intensity of cosmic rays bombarding Earth's surface is largest at the
Poles
On some early automobiles both headlights went out when one bulb burned out. The headlights must have been connected in
Series
A battery's "voltage" is
The amount of energy it gives to each coulomb of electrical charge
Regarding the charges of the electron proton and neutron
The proton has a positive charge, the electron has a negative charge whose strength is EQUAL to the strength of the proton's charge, and the neutron has no charge.
A charged rod carrying a negative charge is brought near two spheres that are in contact with each other but insulated from the ground. If the two spheres are then separated, what kind of charge will be on the spheres?
The sphere near the charged rod becomes positive and the other becomes negative
Object A has an electric charge that is 10 times greater than the charge on Object B. When placed near each other, how does the force by A on B compare with the force by B on A?
They are equal
True or False regarding Resistance. The resistance of a wire is directly proportional to the length of the wire.
True
True or False. Charge flows in a closed circuit
True
True or False. Current flows through a circuit.
True
What makes a uniform electric field?
Very large, closely separated, parallel oppositely charged plates
The unit of electric charge, the coulomb, is the charge on
a specific large number of electrons
Superconductors are noted for their
absence of electric resistance
In an electrical circuit, the number of "amperes" measures the
amount of electric current flowing around the circuit
An uncharged pith ball is suspended by a nylon fiber. When a negatively charged rubber rod is brought nearby, without touching it, the pith ball
becomes polarized
By what method will a positively charged rod produce a negative charge on a conducting sphere that is placed on an insulating surface?
by means of induction
An ampere is a unit of electrical
current
When we say an appliance "uses up electricity," we really are saying that ...
electron kinetic energy is changed into head
Magnet A has twice the Magnetic field strength of magnet B, and at a certain distance pulls on magnet B with a force of 100N. The amount of force that magnet A exerts on magnet B is
exactly 100 N
A plastic rod is charged up by rubbing a wool cloth, and brought to an initially neutral metallic sphere. It is allowed to touch the sphere for a few seconds, and then it separated from the sphere by seconds, and then is separated from the sphere by a small distance. After the rod is separated, the rod
feels no force due to the sphere
Stretch a copper wire so that it is thinner and the resistance between its ends
increases
Electrons move in an electrical circuit by
interacting with an established electric field
To say that electric charge is quantized is to say that the charge on an object
is a whole number multiple of the charge of one electron
Compared to the resistance of two resistors connected in series, the same two resistors connected in parallel have
less resistance