Ch 6 Test Review

contains a piece of metal that melts if the current becomes too high

fuse

A material through which electrons do NOT easily flow is a(n) ____.

insulator

A material through which electrons do NOT readily flow is a(n)____.

insulator

A/An _____ is a material in which charges will not move easily, whereas a/an _____ is a material that allows charges to move about easily.

insulator, conductor

A _____ is equal to 1000 watts delivered continuously for 3,600 seconds

kilowatt-hour

A/An _____ is an energy unit used to measure electric energy use by power companies.

kilowatt-hour

Electric companies usually sell electrical energy in units of ____.

kilowatt-hours

An area with excess electrons has a net _____ charge; an area with a deficit of electrons has a net _____ charge.

negative, positive

What is the effect on the current in a simple circuit when both the voltage and the resistance are divided by 2?

no change

Two objects will attract one another when they have ____.

opposite charges

A circuit that has two or more branches for electrons to follow is a(n) ____.

parallel circuit

A circuit that has two or more separate paths for electrons to follow is a(n)____.

parallel circuit

_____ is described as a property that determines how much current will flow for a given battery voltage.

resistance

_____ is a property that determines how much current will flow for a given source voltage, whereas a _____ is a device that controls the current in a circuit.

resistance, resistor

A __________ is described as a device with specific resistance and is used to control current.

resistor

A _____ is described as a device with specific resistance and is used to control current, whereas a _____ converts chemical energy to electrical energy.

resistor, battery

A path that allows only one route for an electric current is called a ____.

series circuit

A/An _____ is a type of electric circuit in which there is a single current path.

series connection

Electric charge that has accumulated on an object is referred to as ____.

static electricity

If the leaves of an electroscope spread apart, it indicates that ____.

the leaves of the electroscope have received a charge

Three rods of different materials P, Q, and R, are charged by various methods. When the rods are brought near each other, the rods P and Q repel each other, while the rods P and R attract each other. Which of the following could be the signs of the charges on the rods?

- - +

A lamp uses 15 W of power when it is connected across 25 V. What is the current through the lamp?

0.60 A

A lightbulb uses 75 W of power when it is connected across a 125 V source. What current does the lamp draw?

0.60 A

A lightbulb uses 100 W of power when connected across 120 V. What is the current drawn by the lightbulb?

0.8 A

A motor with an operating resistance of 32 ohms is connected to a voltage source. The current in the circuit is 3.8 A. What is the voltage of the source?

1.2 x 102 V

A sensor uses 2.0 10-4 A of current when it is operated by a 3.0 V battery. What is the resistance of the sensor circuit?

1.5 x 104 ohms

A lamp draws a current of 0.50 A when it is connected to a 120 V source? What is the resistance of the lamp?

2.4 x 10^2 ohms

The current going through a car starter is 210 A. If the battery maintains 12 V across the motor, how much electric energy is delivered to the starter in 10.0 s?

2.52 x 104 J

A car battery causes a current of 2.0 A through a lamp and produces 12 V across it. What is the power used by the lamp?

24 W

A car panel lamp has a resistance of 33 ohms when it is placed across a 12 V battery. What is the current through the circuit?

36 A

The current through a lightbulb connected across the terminals of a 125 V outlet is 0.50 A. Assuming 100% efficiency, at what rate does the bulb convert electric energy to light?

63 W

_____ can act from great distances.

Both A and B

One example of a good conductor is ____.

Copper

Which of the following is the correct equation to calculate electrical energy?

E = P × t

Which of the following statements is true about electric forces?

Electric forces cause objects to repel or attract each other

_____ forces between charges are enormous in comparison to _____ forces.

Electrical, gravitational

A conductor is a material that doesn't allow electrons to flow through it easily. ____________________

False

A lightning bolt occurs when billions of protons are transferred at the same time. ____________________

False

A resistor is a device that converts chemical energy into electric energy.

False

A series circuit has more than one path for the electric current to follow.

False

Electrons move freely through an insulator.

False

Ohm's law is the tendency for a material to oppose the flow of electrons. ____________________

False

One kilowatt-hour is equal to the energy consumed by an electric device of 1 W for 1 hour.

False

Opposite charges repel each other.

False

The amount of electrical energy lost as heat and light increases as the resistance decreases.

False

The rule of electric charges can be stated as "like charges attract and unlike charges repel."

False

The unit of power is the kilowatt-hour. ____________________

False

The unit used to measure current is the volt. ____________________

False

The zinc rod forms the positive terminal of a dry cell. ____________________

False

Thunder produces air temperatures hotter than the Sun's surface. ____________________

False

Two objects with the same type of charge attract each other.

False

Using a 1-kW heater for one hour consumes more energy than using a 100-W bulb for one day.

False

Voltage difference is measured in amperes. ____________________

False

In the circuit shown below, which bulb, when burned out, will cause all other bulbs to stop glowing?

Light bulb A

_____charges repel, whereas _____ charges attract.

Like, opposite

Resistance is measured in a unit called the ____.

Ohm

The statement that current is equal to the voltage difference divided by the resistance is known as ____.

Ohm's Law

Which of the following is the correct relationship among power, current, and voltage?

P = I x V

A charged object will induce a separation of charges within a neutral conductor.

True

A fuse is a device used to keep electrical circuits from overheating. ____________________

True

A resistor is a device that controls current in electric circuits.

True

A watt is the amount of power used when a current of 1 A flows through a circuit with a voltage of 1 V.

True

An electric circuit is a closed loop or pathway that allows electric charges to flow.

True

An electric current is a flow of charged particles.

True

Charges added on one part of an insulator remain on that part.

True

Charges added to a conductor quickly spread over the surface of the object.

True

Different household appliances use electrical energy at different rates. ____________________

True

Electric charge is neither created nor destroyed; it is conserved.

True

Electric charges exist within atoms.

True

Electrical current generally increases as voltage increases.

True

Houses, schools, and other buildings are wired using parallel circuits.

True

Like charges repel, whereas opposite charges attract.

True

Objects can be charged by the transfer of electrons.

True

Resistance is a property that determines how much current will flow in a circuit.

True

The flow of electric charge or current that is equal to one coulomb per second is an ampere.

True

The presence of a static electric charge can be detected by an electroscope. ____________________

True

The rearrangement of electrons on a neutral object caused by a nearby charged object is called charging by induction. ____________________

True

Two types of electric charges exist, positive and negative.

True

The carbon rod in a standard D-cell serves as ____.

a conductor to transfer electrons

Lightning is ____.

a large discharge of static electricity

A/An _____ is described as the flow of electric charge or current equal to one coulomb per second.

ampere

The flow of electric charge or current equal to one coulomb per second is a/an _____.

ampere

Electric forces can be either repulsive or attractive, whereas gravitational force is always:

attractive

The direction of the force on a positive test charge near another positive charge is _____ the other charge.

away from

Electric field lines are directed _____ positive charges and _____ negative charges.

away from; toward

A _____ is described as a device that converts chemical energy to electric energy.

battery

Which of the following is a device designed to open an overloaded circuit and prevent overheating?

circuit breaker

Charging by _____ charges a neutral body by touching it with a charged body; whereas charging by _____ charges an object without touching it with a charged body.

conduction, induction

allows electrons to move through it easily

conductor

When two bodies are charged, the total charge before and after charging remains the same because of:

conservation of charges

One source of constant electric current is a ____.

dry cell

A/An _____ is described as a closed loop or pathway that allows electric charges to flow.

electric circuit

A/An _____ is described as a flow of charged particles.

electric current

A/An _____ is described as the flow of charged particles.

electric current

The rate at which an electrical device converts energy from one form to another is called ____.

electrical power

A negatively charged balloon sticks to a wooden door. However, an uncharged balloon does not stick to a wooden door. What is the nature of the charge on the wooden door?

electrically neutral

Normally, atoms are electrically neutral because there are ____.

equal numbers of protons and electrons

When a conducting sphere is charged positively, initially the charge is deposited on the left side. However, due to the sphere's conducting nature, the charge spreads uniformly throughout the surface of the sphere. Charge is uniformly distributed because:

excess electrons within the sphere move toward excess protons