Science Chapters 6 and 7 Worksheets

i

(c or i) Bulletin board:

i

(c or i) Carpet:

i

(c or i) Clothing:

c

(c or i) Copper:

c

(c or i) Gold:

c

(c or i) Metal coat hanger:

c

(c or i) Metal doorknob:

c

(c or i) Paper clip:

i

(c or i) Plastic:

i

(c or i) Rubber:

c

(c or i) Silver:

i

(c or i) Wood:

wet

A car battery is an example of a (dry, wet) cell.

a

A car battery is an example of a _____. a) wet cell b) dry cell

a

A circuit that has two or more separate branches for current is a _____. a. parallel circuit b. series circuit c. circuit diagram d. electron circuit

b

A closed path through which electrons can flow is _____. a) voltage b) a circuit

b

A current has two or more branches in a _____. a) series circuit b) parallel circuit

a

A dry cell is used in a flashlight to convert _____ to light. a) electrical energy b) static electricity

a

A fuse will melt if the _____ in a circuit becomes too high. a) current b) resistance

b

A material through which electrons do not move easily is a _____. a. transformer b. insulator c. conductor d. fuse

more

A negatively charged object has (more, fewer) electrons than an object that is neutral.

d

A path that allows only one route for a current is called a _____. a. series current b. parallel current c. parallel circuit d. series circuit

b

A power rating lists the _____ required to operate an appliance. a) voltage b) watts

b

A static discharge differs from an electric current in that a static discharge _____. a. is a flow of electrons b. lasts for only a fraction of a second c. results because a force is exerted on the electrons d. involves the movement of ions as well as electrons

c

A television that requires an average of 0.4 ampere of current is operated on a 120-volt service for 5 hours. How much energy is used? a. 1.5 kWh b. 0.15 kWh c. 0.24 kWh d. 0.67 kWh

lesser

A wire with a resistance of 3Ω has a (greater, lesser) resistance to electron flow than a wire with a resistance of 5Ω.

I = V/R

According to Ohm's law, (I = V/R, V = I/R).

static electricity

Accumulation of electric charges on an object:

electroscope

An _____ is a device that can detect the presence of electric charges.

conductor

Any material that allows electricity to pass through it easily:

d

Circuit breaker: a. how much power an appliance uses b. individual batteries c. a small piece of wire that melts d. a piece of metal that bends e. tendency of a material to oppose the flow of electrons f. no current flows in this circuit

lower

Copper has a (higher, lower) resistance to electron flow than tungsten.

b

Current has only one loop to flow through in a _____. a) parallel circuit b) series circuit

electrons

Current is almost always the flow of (electrons, protons).

a

Current is almost always the flow of _____. a) electrons b) protons

b

Current is measured in _____. a) volts b) amperes

b

Dry cell: a. how much power an appliance uses b. individual batteries c. a small piece of wire that melts d. a piece of metal that bends e. tendency of a material to oppose the flow of electrons f. no current flows in this circuit

c

Electric charge that has accumulated on an object is referred to as _____. a. current electricity b. circuit electricity c. static electricity d. current circuit

a

Electrical energy is equal to _____ x time. a) power b) voltage

a

Electrical power is equal to _____ x voltage difference. a) current b) ohms

higher, lower

Electrons flow from areas of (higher, lower) voltage to areas of (higher, lower) voltage.

lose

Electrons passing through a lamp (gain, lose) some voltage as they light the lamp.

electric field

Exerts a force on anything that has an electric charge:

c

Fuse: a. how much power an appliance uses b. individual batteries c. a small piece of wire that melts d. a piece of metal that bends e. tendency of a material to oppose the flow of electrons f. no current flows in this circuit

160 Ω

If a current flowing through a lightbulb is 0.75 ampere and the voltage difference across the lightbulb is 120 volts, how much resistance does the light but have?

112 kWh

If a family used 999 kilowatt-hours of electrical energy in the period between the November and December readings, how much more energy did they use in the following one-month period if they used 1,111 kWh?

8.6 A

If an air conditioner uses 1800 watts of power when plugged into a wall socket that operates at a voltage of 210 volts, what is the current flowing through the air conditioner to one decimal place?

$111.10

If electricity costs $0.10 per kilowatt-hour, how much was the electric bill in January if they used 1,111 kWh?

1,111 kwh

If the reading on an electric meter in December was 2345 kilowatt-hours and the reading in January was 3456 kilowatt-hour, how much electrical energy was used in the one-month period between the December and January readings?

thinner

If two copper wires are the same length, but different thicknesses, the (thinner, thicker) wire has greater resistance.

positive

In a dry cell, the carbon rod releases electrons and becomes the (positive, negative) terminal.

amperes

In the equation I = V/R, I is expressed in (ohms, amperes).

volts

In the equation I = V/R, V is expressed in (volts, ohms).

a

Lightning is _____. a. a very large discharge of static electricity b. a buildup of neutrons c. a low voltage electric current d. harmless

ok

Look at numbers 6 through 10 on p.39.

insulator

Material that does not allow an electric current to pass through it easily:

plastic

Material that is often used to insulate wires that conduct electricity:

metals

Materials that usually are good conductors of electricity:

electrical energy, kilowatt-hour

Measurement: _____ Unit: _____ Symbol: kWh

electric current, A

Measurement: _____ Unit: amperes Symbol: _____

resistance, Ω

Measurement: _____ Unit: ohm Symbol: _____

watts, W

Measurement: electrical power Unit: _____ Symbol: _____

volts, V

Measurement: voltage difference Unit: _____ Symbol: _____

copper

Metal that is often used in wires that conduct electricity:

repel

Negative and negative charges will:

electrons

Negatively charged particles that are found outside the nucleus of an atom:

neutrons

Neutral particles found in the nucleus of an atom:

b

Ohm's law states that the current equals _____ divided by the resistance. a) amperes b) voltage difference

c

One source of constant electric current is a _____. a. switch b. transformer c. dry cell d. coulomb

b

One thousand watts of power is used in 60 minutes is _____. a) 16.7 amperes b) 1 Kilowatt-hour

f

Open circuit: a. how much power an appliance uses b. individual batteries c. a small piece of wire that melts d. a piece of metal that bends e. tendency of a material to oppose the flow of electrons f. no current flows in this circuit

attract

Positive and negative charges will:

repel

Positive and positive charges will:

protons

Positively charged particles that are found in the nucleus of an atom:

ohms

Resistance is measured in (ohms, volts).

b

Resistance is measured in a unit called the _____. a. ampere b. ohm c. volt d. coulomb

e

Resistance: a. how much power an appliance uses b. individual batteries c. a small piece of wire that melts d. a piece of metal that bends e. tendency of a material to oppose the flow of electrons f. no current flows in this circuit

You could take out one light. If all the lights go out, it is a series circuit. If some of the lights stay on, it is a parallel circuit.

Suppose you have purchased a string of lights. You want to find out if the lights are wired in a series or in parallel. How could you quickly determine how the lights have been wired?

+

The (+, -) terminal of a dry cell identifies the location of the carbon rod.

amperes

The current in a circuit is measured in (volts, amperes).

c

The rate at which an electrical device converts energy from one form to another is called _____. a. electrical energy b. electrical resistance c. electrical power d. voltage regulation

a

The statement, current is equal to the voltage difference divided by the resistance, is known as _____. a. Ohm's law b. Newton's law c. Einstein's equation d. Faraday's law

Ω

The symbol for ohms is (Ω, °).

b

The tendency for a material to oppose the flow of electrons is called _____. a) voltage b) resistance

b

The voltage _____ as current moves through a circuit. a. remains the same b. varies c. doubles d. increases

120 volts

The voltage difference between the two holes in a wall socket is (12 volts, 120 volts).

a

Thin wires have a _____ resistance to electron flow than do thicker wires. a) greater b) lesser

varies

Voltage (varies, is the same) in all parts of a series circuit.

volts

Voltage difference is measured in (amperes, volts).

Lightning is a very large discharge of static electricity. As electric charges move through the air, they collide with molecules, which emits light.

What causes lightning?

An electroscope is a device that can detect electric charge. It has two metal leaves attached to a metal rod with a metal knob at the top. If a charged object touches the knob, the leaves repel each other.

What is an electroscope and how does it work?

A balloon gains electrons, and your hair loses them. This makes the balloon negatively charged. Glass gives electrons to silk when they are rubbed together. This makes the glass positively charged.

What is the difference in the charges on a balloon rubbed in your hair and a glass rod rubbed with silk? Why?

repel

What like charges do:

attract

What unlike charges do:

positive, negative

When a dry cell is connected in a series, the flow of electrons moves from the (positive, negative) terminal to the (positive, negative) terminal.

d

Which of the following is a device designed to open an overloaded circuit and prevent overheating? a. transformer b. magnet c. resistor d. circuit breaker

c

Which of the following is the correct relationship among power, current, and voltage? a. P = I/V b. V = P x I c. P = I x V d. Ω = P x I