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