# electric circuits

## parts of an electric circuit

All electric circuits have at least two parts: a voltage source and a conductor. The voltage source of the circuit in Figure 23.16 is a battery. In a home circuit, the source of voltage is an electric power plant, which may supply electric current to many homes and businesses in a community or even to many communities. The conductor in most circuits consists of one or more wires. The conductor must form a closed loop from the source of voltage and back again. In Figure 23.16, the wires are connected to both terminals of the battery, so they form a closed loop. The circuit in Figure 23.16 also has two other parts: a light bulb and a switch. Most circuits have devices such as light bulbs that convert electric energy to other forms of energy. In the case of a light bulb, electricity is converted to light and thermal energy. Many circuits have switches to control the flow of current through the circuit. When the switch is turned on, the circuit is closed and current can flow through it. When the switch is turned off, the circuit is open and current cannot flow through it.

## circuit diagrams

When a contractor builds a new home, she uses a set of plans called blueprints that show her how to build the house. The blueprints include circuit diagrams that show how the wiring and other electrical components are to be installed in order to supply current to appliances, lights, and other electrical devices in the home. You can see an example of a very simple circuit diagram in Figure 23.17. Different parts of the circuit are represented by standard symbols, as defined in the figure. An ammeter measures the flow of current through the circuit, and a voltmeter measures the voltage. A resistor is any device that converts some of the electricity to other forms of energy. It could be a light bulb, doorbell, or similar device.

## electric power and electrical energy use

We use electricity for many purposes. Devices such as lights, stoves, and stereos all use electricity and convert it to energy in other forms. However, devices may vary in how quickly they change electricity to other forms of energy.

## series and parallel circuits

There are two basic types of electric circuits, called series and parallel circuits. They differ in the number of loops through which current can flow. You can see an example of each type of circuit in Figure 23.18. A series circuit has only one loop through which current can flow. If the circuit is interrupted at any point in the loop, no current can flow through the circuit and no devices in the circuit will work. In the series circuit in Figure 23.18, if one light bulb burns out the other light bulb will not work because it wont receive any current. Series circuits are commonly used in flashlights. You can see an animation of a series circuit at this URL: http://regentsprep.org/regents/physics/phys03/bsercir/default.htm . A parallel circuit has two (or more) loops through which current can flow. If the circuit is interrupted in one of the loops, current can still flow through the other loop(s). For example, if one light bulb burns out in the parallel circuit in Figure 23.18, the other light bulb will still work because current can by-pass the burned-out bulb. The wiring in a house consists of parallel circuits. You can see an animation of a parallel circuit at this URL: http://regentsprep.org/regents/physics/phys03/bsercir/default.htm .

## electrical energy use

Did you ever wonder how much electrical energy it takes to use an appliance such as a microwave or hair dryer? Electrical energy use depends on the power of the appliance and how long it is used. It can be represented by the equation: Electrical Energy = Power Time 1 Suppose you use a 1.2-kilowatt microwave for 5 minutes ( 12 hour). Then the energy used would be: Electrical Energy = 1.2 kilowatts 1 hour = 0.1 kilowatt-hours 12 Electrical energy use is typically expressed in kilowatt-hours, as in this example. How much energy is this? One kilowatt-hour equals 3.6 million joules of energy. Therefore, the 0.1 kilowatt-hours used by the microwave equals 0.36 million joules of energy. You Try It! Problem: A family watches television for an average of 2 hours per day. The television has 0.12 kilowatts of power. How much electrical energy does the family use watching television each day?

## electric power

The rate at which a device changes electric current to another form of energy is called electric power. The SI unit of powerincluding electric poweris the watt. A watt equals 1 joule of energy per second. High wattages are often expressed in kilowatts, where 1 kilowatt equals 1000 watts. The power of an electric device, such as a microwave, can be calculated if you know the current and voltage of the circuit. This equation shows how power, current, and voltage are related: Power (watts) = Current (amps) Voltage (volts) Consider a microwave that is plugged into a home circuit. Assume the microwave is the only device connected to the circuit. If the voltage of the circuit is 120 volts and it carries 10 amps of current, then the power of the microwave is: Power = 120 volts 10 amps = 1200 watts, or 1.2 kilowatts You Try It! Problem: A hair dryer is connected to a 120-volt circuit that carries 12 amps of current. What is the power of the hair dryer in kilowatts?

## how a short circuit occurs

An electric cord contains two wires. One wire carries current from the outlet to the appliance or other electric device, and one wire carries current back to the outlet. Did you ever see an old appliance with a damaged cord, like the one in Figure 23.19? A damaged electric cord can cause a severe shock if it allows current to pass from the cord to a person who touches it. A damaged cord can also cause a short circuit. A short circuit occurs when electric current follows a shorter path than the intended loop of the circuit. For example, if the two wires in a damaged cord come into contact with each other, current flows from one wire to the other and bypasses the appliance. This may cause the wires to overheat and start a fire.

## electric circuit basics

A closed loop through which current can flow is called an electric circuit. In homes in the U.S., most electric circuits have a voltage of 120 volts. The amount of current (amps) a circuit carries depends on the number and power of electrical devices connected to the circuit. But home circuits generally have a safe upper limit of about 20 or 30 amps.

## using electricity safely

Even with electric safety features, electricity is still dangerous if it is not used safely. Follow the safety rules below to reduce the risk of injury or fire from electricity. Never mix electricity and water. Dont turn on or plug in electric lights or appliances when your hands are wet, you are standing in water, or you are in the shower or bathtub. The current could flow through the waterand youbecause water is a very good electric conductor. Never overload circuits. Avoid plugging too many devices into one outlet or extension cord. The more devices that are plugged in, the more current the circuit carries. Too much current can overheat a circuit and start a fire. Never use devices with damaged cords or plugs. They can cause shocks, shorts, and fires. Never put anything except plugs into electric outlets. Plugging in other objects is likely to cause a serious shock that could be fatal. Never go near fallen electric lines. They could be carrying a lot of current. Report fallen lines to the electric company as soon as possible.

## electric safety

Electricity is dangerous. Contact with electric current can cause severe burns and even death. Electricity can also cause serious fires. A common cause of electric hazards and fires is a short circuit.

## electric safety features

Because electricity can be so dangerous, safety features are built into electric circuits and devices. They include three-prong plugs, circuit breakers, and GFCI outlets. Each feature is described and illustrated in Table 23.1. You can learn more about electric safety features in the home by watching the video at this URL: Electric Safety Feature Three-Prong Plug Circuit Breaker Description A three-prong plug is generally used on metal appli- ances. The two flat prongs carry current to and from the appliance. The round prong is for safety. It connects with a wire inside the outlet that goes down into the ground. If any stray current leaks from the circuit or if there is a short circuit, the ground wire carries the current into the ground, which harmlessly absorbs it. A circuit breaker is a switch that automatically opens a circuit if too much current flows through it. This could happen if too many electric devices are plugged into the circuit or if there is an electric short. Once the problem is resolved, the circuit breaker can be switched back on to close the circuit. Circuit breakers are generally found in a breaker box that controls all the circuits in a building. Electric Safety Feature GFCI Outlet Description GFCI stands for ground-fault circuit interrupter. GFCI outlets are typically found in bathrooms and kitchens where the use of water poses a risk of shock (because water is a good electric conductor). A GFCI outlet contains a device that monitors the amounts of current leaving and returning to the outlet. If less current is returning than leaving, this means that current is escaping. When this occurs, a tiny circuit breaker in the outlet opens the circuit. The breaker can be reset by pushing a button on the outlet cover.

## instructional diagrams

In this figure, you see a Series and a Parallel circuit. The circuits are composed of one battery, two lamps and wires. The battery provides the required voltage for these circuits, and the wire is used to conduct the electricity between different components of the circuit. The Series circuit is shown on the left and the Parallel circuit is shown on the right. There is only one loop in the Series circuit, while the Parallel circuit has two loops. The lamps in the Series circuit will be turned off if one of the circuit components get disconnected. However, one of the lamps in the Parallel circuit will remain on even if the other lamp is disconnected.

The diagram we see here is that of an electric circuit. There are four components in this circuit-the battery, the switch, the wire and the light bulb. The light bulb shall work only when it is connected to the battery. If the wire is connected loosely, the light bulb won't light because electric current needs a smooth path to flow the current. Wire is a very essential component as the current flows through the wire. Charges must have an unbroken path to follow between the positively and negatively charged parts of the voltage source, in this case, the battery. Electric current cannot flow through an open circuit. A switch controls the flow of current through the circuit. When the switch is turned on, the circuit is closed and current can flow through it. When the switch is turned off, the circuit is open and current cannot flow through it.

The diagram shows both an open and closed circuit. Each circuit contains wires connected to each terminal of the battery along with a light bulb. Each battery contains two terminals, a positive and negative. The positive side is shown with a plus symbol. In the closed circuit, electrons are allowed to flow and illuminate the light bulb. The flow of electrons are shown by the arrows from the positive to the negative terminal through the light bulb. In the open circuit, the wire connected to the negative terminal is not connected to the light bulb. This prevents electrons from flowing through the circuit and the light bulb does not get illuminated.

The diagram shows a parallel circuit with a battery and 4 resistors. A parallel circuit has two or more paths for current to flow through. All electric circuits have at least two parts: a voltage source and a conductor. The voltage source of the circuit in the diagram is a battery. Voltage is the same across each component of the parallel circuit. The conductor must form a closed loop from the source of voltage and back again. From the diagram, the wires are connected to both terminals of the battery, so they form a closed loop. The diagram also has 4 resistors, which can be any device (such as a lightbulb) that converts some electricity to other forms of energy.

This diagram shows an open circuit. It consists of a bulb, a battery and wires connecting the bulb to the battery. The battery has two terminals, a positive and a negative terminal. A and B are the ends of the wire. In this diagram, A and B are not connected to each other. Hence the circuit is called an open circuit. Electric current cannot flow through an open circuit. Hence the bulb will not light up. If the ends of the wires, A and B were connected to each other, the circuit would be known as a closed circuit. Electric current would flow through this closed circuit which would lead the bulb to be lit.

## questions

Most home circuits have a voltage of

``````a. 20 volts.

b. 30 volts.

c. 60 volts.

-->  d. 120 volts.
``````

Most home circuits can carry a maximum current of about

``````a. 240 amps.

b. 120 amps.

c. 60 amps.

-->  d. 30 amps.
``````

How many resistors are there in the circuit represented by this circuit diagram?

``````a. 1

b. 2

c. 3

-->  d. 4
``````

The source of voltage in home electric circuits is a(n)

``````a. electric outlet.

b. large battery.

-->  c. power plant.

d. breaker box.
``````

Electric power is expressed in the SI unit called the

``````-->  a. watt.

b. ohm.

c. amp.

d. volt.
``````

Which of the following symbols represents a battery in a circuit diagram?

``````a. 12 kilowatts

b. 1.2 kilowatts

-->  c. 0.2 kilowatts

d. 0.1 kilowatts
``````

Which units are used to measure electrical energy use?

``````a. amps

b. ohms

c. watts

-->  d. kilowatt-hours
``````

The power of an electric device can be calculated if you know the circuits

``````a. resistance.

b. voltage.

c. current.

-->  d. two of the above
``````

The electrical energy used by a 1000-watt microwave that runs for 30 minutes is

``````-->  a. 0.5 kilowatt-hours.

b. 3.0 kilowatt-hours.

c. 15 kilowatt-hours.

d. 500 kilowatt-hours.
``````

A ground-fault circuit interrupter is found in

``````a. almost all electrical devices.

b. the main breaker box in a house.

-->  c. some electrical outlets.

d. all of the above
``````

Which of the following is an electric safety rule?

``````a. Never go near fallen electric lines.

b. Do not plug too many devices into one outlet.

c. Never plug in electric devices when your hands are wet.

-->  d. all of the above
``````

any device that converts some of the electricity in a circuit to another form of energy

``````a. ammeter

b. series circuit

c. electric circuit

d. electric power

e. switch

f. parallel circuit

-->  g. resistor
``````

any closed loop through which electric current can flow

``````a. ammeter

b. series circuit

-->  c. electric circuit

d. electric power

e. switch

f. parallel circuit

g. resistor
``````

rate at which a device changes electric current to another form of energy

``````a. ammeter

b. series circuit

c. electric circuit

-->  d. electric power

e. switch

f. parallel circuit

g. resistor
``````

All electric circuits must include a voltage source and a switch.

``````a. true

-->  b. false
``````

circuit with two (or more) loops through which current can flow

``````a. ammeter

b. series circuit

c. electric circuit

d. electric power

e. switch

-->  f. parallel circuit

g. resistor
``````

Electrical energy use is a product of current and time.

``````a. true

-->  b. false
``````

device that measures the flow of current through a circuit

``````-->  a. ammeter

b. series circuit

c. electric circuit

d. electric power

e. switch

f. parallel circuit

g. resistor
``````

device used to control the flow of current in a circuit

``````a. ammeter

b. series circuit

c. electric circuit

d. electric power

-->  e. switch

f. parallel circuit

g. resistor
``````

GFCI outlets are used in kitchens and bathrooms.

``````-->  a. true

b. false
``````

circuit with one loop through which current can flow

``````a. ammeter

-->  b. series circuit

c. electric circuit

d. electric power

e. switch

f. parallel circuit

g. resistor
``````

Water is a very good electrical conductor.

``````-->  a. true

b. false
``````

A damaged electric cord can cause an electric short.

``````-->  a. true

b. false
``````

Electric current can flow through a circuit only if it forms a closed loop.

``````-->  a. true

b. false
``````

Most home circuits can safely carry 120 amps of current.

``````a. true

-->  b. false
``````

A more powerful electric device changes electric current to another form of energy in less time.

``````-->  a. true

b. false
``````

All electric circuits must have at least four parts.

``````a. true

-->  b. false
``````

When a circuit is closed, current cannot flow through it.

``````a. true

-->  b. false
``````

A circuit diagram uses standard symbols to represent the parts of a circuit.

``````-->  a. true

b. false
``````

The wiring in a house consists of parallel circuits.

``````-->  a. true

b. false
``````

The power of an electric device is a product of voltage and time.

``````a. true

-->  b. false
``````

A less powerful electric device uses less energy in the same amount of time as a more powerful device.

``````-->  a. true

b. false
``````

Dangers of electricity include burns and fires.

``````-->  a. true

b. false
``````

## diagram questions

What transfers energy to the furthest bulb?

``````a. battery

b. the closest bulb

-->  c. Copper wire

d. the parallel circuit
``````

If one bulb goes out what will happen to the other?

``````-->  a. It will stay on

b. It will explode

c. It will flicker

d. They will both go out
``````

What type of circuit is represented by the drawing and diagram?

``````a. Interrupted circuit

b. Series circuit

-->  c. Parallel circuit

d. Short circuit
``````

If the lightbulb at the top burns out, would the one below still work?

``````-->  a. Yes

b. No

c. Intermittenedly

d. Not enough information to determine
``````

How many light bulbs does the battery in the diagram power?

``````a. 3

b. 4

c. 1

-->  d. 2
``````

If one lightbulb goes out, what will happen?

``````-->  a. nothing

b. the other light will brighten

c. the other light will also go out

d. the other light will dim
``````

If the cell has no power left will the bulbs still work?

``````a. Yes

-->  b. No

c. Yes in the first diagram but not in the second

d. Not in the first diagram but yes in the second
``````

What is this diagram all about?

``````a. Solar Energy

b. Life Cycle

-->  c. Electric Circuit

d. Optic Circuit
``````

Identify the part that provides energy to this circuit.

``````a. The filament

b. The wire

c. The light blub

-->  d. The battery
``````

What happens when you correctly connect a bulb to a battery?

``````-->  a. It lights

b. It explodes

c. It flashes

d. Nothing
``````

If the first light is off will the second light also be off?

``````a. only if the wires are red

-->  b. yes

c. only if the lights are 3 inches apart

d. no
``````

What would happen if I removed the battery from the circuit?

``````a. One light would turn off.

b. One light would stay on.

c. The lights would stay on.

-->  d. The lights would turn off.
``````

How many of the shown configurations will work?

``````a. 1

b. 3

c. 4

-->  d. 2
``````

If the light bulb below burns out, would the one at the top still burn?

``````a. No

-->  b. Yes

c. Cannot determine from the given information

d. Intermittently
``````

How many lamps are used in the circuit shown below?

``````a. 4

-->  b. 3

c. 5

d. 2
``````

How many light bulbs does the battery power?

``````a. 4

b. 2

-->  c. 3

d. 1
``````

What kind of electric circuit is shown in the figure?

``````a. Combined circuit

b. I don't know

-->  c. Series circuit

d. Parallel circuit
``````

How many lamps are in this diagram?

``````-->  a. 4

b. 1

c. 2

d. 3
``````

How many series are depicted in the diagram?

``````-->  a. 2

b. 4

c. 1

d. 3
``````

What is the difference between the parallel and series circuits?

``````a. There is no difference between the two circuits

-->  b. In the series if the circuit is interrupted neither light will work on the parallel at least one light will work

c. In the parallel circuit neither light would work

d. In the series circuit one light will continue to work
``````

How many lights are shown in this diagram?

``````a. 4

b. 1

c. 3

-->  d. 2
``````

What type of switch is represented in this diagram?

``````a. Parallel Switch

b. Junction Switch

-->  c. Open Switch

d. Closed Switch
``````

What will happen when the switch is closed?

``````a. the lights will flash

b. nothing will occur

-->  c. the lights will turn on

d. only one light will turn on
``````

What part of the Circuit would you Open to Break the Flow of Electricity?

``````a. Battery

b. Bulb

c. Wires

-->  d. Switch
``````

Where would the electricity go from the positive side of the battery?

``````a. middle light bulb

-->  b. switch

c. none

d. top light bulb
``````

How many light bulbs are included in the circuit?

``````-->  a. 3

b. 1

c. 4

d. 2
``````

How many light bulbs does the battery power?

``````a. 1

-->  b. 3

c. 2

d. 4
``````

What type of switch is represented in this diagram?

``````a. Open Switch

-->  b. Closed Switch

c. No Switch

d. Positive Switch
``````

What would happen if two of the light bulbs are removed and the circuit is reconnected?

``````-->  a. The remaining light bulb brightness will increase

b. The remaining bulb brightness will decrease

c. The remaining bulb will not light up

d. No change in the brightness of the remaining bulb
``````

Current flows TO which end of the source (battery)?

``````a. Light bulb

b. Positive

c. Wire

-->  d. Negative
``````

What gives the lightbulb energy?

``````-->  a. Battery

b. Water

c. Air

d. Light
``````

How many bulbs are shown in the diagram?

``````a. 2

b. 4

-->  c. 1

d. 3
``````

If the wire was loose on the positive end of the battery, will the light bulb still light up?

``````a. yes

-->  b. no

c. Not enough information

d. It will come on and off repeatedly.
``````

What would happen to the light bulb if the current was interrupted?

``````a. It would flicker

b. It would explode

-->  c. It would turn off

d. It would remain on
``````

How many broken bulbs are in the diagram?

``````-->  a. 2

b. 4

c. 3

d. 1
``````

In a parallel circuit, how many lamps can break to force all the other lamps to turn down?

``````a. 3

-->  b. All of them.

c. 2

d. 4
``````

Why do lamps stay lit in parallel circuits?

``````a. There is only one loop

-->  b. There's two or more loops through which the current can flow

c. The battery is powerful

d. There's still enough electricity to go around
``````

What does the symbol X with a circle around it, represent in the diagram on the right?

``````a. Wire

b. Circut

-->  c. Lightbulb

d. Battery
``````

How many batteries are shown in this diagram?

``````-->  a. 2

b. 4

c. 3

d. 1
``````

What happens to the other bulb if one of the other bulbs was switched off?

``````a. I don't know

-->  b. The second bulb will stay on.

c. The second bulb stops running.

d. The second bulb will turn off.
``````

What type of circuit is represented?

``````a. Series Circut

-->  b. Parallel Circut

c. No Circut

d. Negative Circut
``````

In this circuit, what happens if you open the switch?

``````a. Bulbs flash

b. Bulbs explode

c. Nothing

-->  d. The lights go out
``````

What will happen if the switch will be closed (turned on)

``````a. the wires will be destroyed

b. the battery will explode

c. the switch will melt

-->  d. the bulb will light
``````

How many light bulbs are shown in this chart?

``````-->  a. 3

b. 2

c. 1

d. 4
``````

What is depicted as S?

``````a. Battery

-->  b. Switch

c. Cable

d. Light Bulb
``````

How many bulbs are shown in this picture?

``````-->  a. 3

b. 2

c. 4

d. 5
``````

How many closed switches are in this diagram?

``````a. 3

-->  b. zero

c. 2

d. 1
``````

What is shown in the diagram?

``````a. Energy Power

b. Solar Energy

-->  c. Electric Circuits

d. Nuclear Power
``````

What type of switch is represented in this diagram?

``````a. No Switch Shown

b. Positive Switch

-->  c. Open Switch

d. Closed Switch
``````

Where does the lightbulb get energy from?

``````a. Wall

b. Wire

c. Light

-->  d. Battery
``````

How many bulbs does this battery power?

``````a. 2

b. 5

c. 3

-->  d. 1
``````

In the picture, what does the yellow represent?

``````a. cable

b. plug

c. battery

-->  d. horn
``````

If an electrical circuit has a switch, the circuit can be completed when the switch is:

``````a. A Resistor

-->  b. Closed

c. Open

d. Broken
``````

When the switch is closed where does the energy from the battery go?

``````-->  a. horn

b. wire

c. switch

d. battery
``````

How many switches are present in the circuit?

``````a. 3

b. 2

c. 4

-->  d. 1
``````

Where does the red wire from the battery connected to?

``````a. none

b. other end of battery

-->  c. light bulb

d. switch
``````

How many wires are shown in this diagram?

``````a. 1

-->  b. 3

c. 2

d. 4
``````

If the switch is removed, what should be done to make the light bulb work?

``````-->  a. The wire ends from the removed switch should be connected.

b. The battery must be removed and replaced with AC power.

c. The light bulb must be replaced with a brighter one.

d. The battery must be replaced with a higher capacity one.
``````

What is the electrical component that can break an electrical circuit, interrupting the current?

``````a. Battery

-->  b. Switch

c. Conductor

d. Light Bulb
``````

How many objects are required to light a bulb?

``````a. 3

b. 4

c. 1

-->  d. 2
``````

Which direction does the electricity flow?

``````a. Right to left

b. Down

c. Up

-->  d. Left to Right
``````

How many batteries appear in the image?

``````a. 2

b. 4

c. 3

-->  d. 1
``````

Would the bulb glow forever?

``````a. Data Insufficient

-->  b. No

c. Not sure

d. Yes
``````

What part of the circuit is in between the bulb and battery? It opens and closes the circuit.

``````a. Wire

b. Battery

c. Bulb

-->  d. switch
``````

How many batteries are required to get to the bulbs to light?

``````-->  a. 1

b. 4

c. 7

d. 5
``````

How many light bulbs does the battery power?

``````-->  a. 3

b. 5

c. 1

d. 2
``````

If the first bulb goes out, which of the following bulbs will still work?

``````-->  a. The second and the third

b. They all will go out

c. Only the third

d. Only the second
``````

The bulb should be connected to what in order to light up?

``````a. The negative pole

b. Either pole

c. The positive pole

-->  d. Both battery poles
``````

How many batteries are shown in this diagram?

``````a. 3

b. 1

c. 4

-->  d. 2
``````

How many bulbs are shown in the figure?

``````a. 2

b. 3

-->  c. 1

d. 4
``````

Which part of the circuit is represented by the 'X' inside a circle?

``````a. Battery

b. Switch

-->  c. Light globe

d. Resistor
``````

What type of circuit is the one on the right?

``````-->  a. Parallel Circut

b. Simple Circut

c. Basic Circut

d. No Circut
``````

Why is the left circuit have no bulbs lighted up?

``````a. The left circuit needs an on-off switch to function.

b. The left circuit battery just needs to be replaced with a more powerful one.

c. The right circuit is cheating and has a self-lighting bulb.

-->  d. The circuit is connected in series, so the circuit is open when a bulb is broken.
``````

How many bulbs are shown in the diagram?

``````a. 2

-->  b. 1

c. 4

d. 3
``````

What type of circuit does this diagram depict?

``````a. Open Circuit

b. Loop Circuit

c. Parallel Circuit

-->  d. Closed Circuit
``````

What is Providing Energy in this Circuit

``````-->  a. Battery

b. Wires

c. Bulb

d. Screws
``````

How many battery connections are shown in this diagram?

``````-->  a. 2

b. 1

c. 3

d. 4
``````

What type of metal is needed for electricity to flow?

``````-->  a. Conductive metal

b. insulating metal

c. wet metal

d. gold metal
``````

Where does the energy go after leaving the positive side of the battery?

``````-->  a. left light bulb

b. battery

c. right light bulb

d. middle light bulb
``````

How many bulbs are there in a series circuit?

``````-->  a. 3

b. 5

c. 4

d. 2
``````

What happens if the battery runs out of power?

``````a. The second bulb will turn off.

-->  b. All light bulbs will turn off.

c. The first bulb near the positive charge of the battery will turn off.

d. The third bulb will turn off.
``````

What in the provided image is known as the voltage source of the circuit?

``````a. The black wire

b. The light bulb

-->  c. The battery

d. The red wire
``````

How many batteries are need to make a simple short circuit?

``````a. 4

b. 3

-->  c. 1

d. 2
``````

In an actual electric circuit shown, which element is represented by the plus (+) and minus (-) symbols?

``````a. circuit board

-->  b. battery

c. wire

d. bulb
``````

What turns the light on and off?

``````a. button

-->  b. the switch

c. sunlight

d. the light
``````

What would happen if the switch was opened?

``````a. The light will get brighter

b. the light will dim

-->  d. the light would shut off.
``````

What is the current in this diagram?

``````a. 120W

b. 60W

c. 60V

-->  d. 120V
``````

Where does the energy go after leaving the source, assuming the switch is closed?

``````a. right bulb

-->  b. the bulbs

c. left bulb

d. wire
``````

In this circuit, what would happen if one light bulb burns out?

``````a. If one light bulb burns out the other light bulb will still work because of its stored current.

b. If one light bulb burns out the other light bulb will not work because the amount of current would be too high for the other light bulb.

-->  c. If one light bulb burns out the other light bulb will not work because it wont receive any current.

d. If one light bulb burns out the other light bulb will still work because current can by-pass the burned-out bulb.
``````

After energy leaves the positive side of the battery (assuming the switch is closed) where does it go?

``````a. battery

b. bottom bulb

-->  c. the top bulb

d. middle bulb
``````

How many batteries are there in a series circuit?

``````a. 4

b. 3

c. 2

-->  d. 1
``````

If I opened the switch what would happen?

``````a. The energy flow would increase.

b. The battery will disappear.

c. The lights would become brighter.

-->  d. The lights would go out.
``````

How many lamps are shown in this image?

``````a. 2

b. 4

c. 1

-->  d. 3
``````

How many bulbs are shown in the figure?

``````a. 1

-->  b. 3

c. 4

d. 2
``````

If the switch is off, what happens?

``````-->  a. All lamps go off

b. All lamps light up

c. Nothing

d. Lamp A lights up and lamp B and C go out
``````

How many lamps are shown in this diagram?

``````a. 2

-->  b. 3

c. 1

d. 4
``````

How many switches are required for three lamps?

``````a. two

-->  b. one

c. three

d. four
``````

Which lamps would turn on if switch is connected?

``````-->  a. B

b. A

c. A,B,C

d. C
``````

What kind of switch does this diagram represent?

``````a. Electron Flow

-->  b. Open Switch

c. Closed Switch

d. Battery
``````

How many light bulbs are used in this circuit?

``````a. 6

b. 4

c. 2

-->  d. 1
``````

How would remove the battery affect the current flow?

``````a. The switch would provide the flow.

-->  b. The flow would stop.

c. The flow would stay the same.

d. The flow would increase.
``````

What color is the battery in the two circuits?

``````-->  a. Red

b. White

c. Black

d. Blue
``````

In the parallel circuit what would happen if one of the bulbs were to blow out?

``````a. The other bulb would flicker

b. The other bulb would also blow out

-->  c. The other bulb would continue to work normally

d. The other bulb would go out
``````

The wires between the battery, bulb and switch are called?

``````a. sources

c. controls

-->  d. conductors
``````

What part of the circuit controls the flow of energy?

``````a. light bulb

-->  b. on/off swith

c. battery

d. wires
``````

What happens when the Single Dry Cell runs out of power?

``````a. The bulb stays lit until the switch is off

-->  b. The bulb turns off

c. Nothing

d. The bulb stays lit
``````

The negative end of the battery is depicted by:

``````a. Switch

b. Motor

-->  c. -

d. +
``````

Where does the energy go after leaving the positive side of the battery?

``````a. resistor

b. light bulb

-->  c. motor

d. negative side
``````

How many motors are shown in this diagram?

``````a. 2

-->  b. 1

c. 3

d. 4
``````

How many sides are there in a battery in the diagram below?

``````a. 3

b. 4

-->  c. 2

d. 1
``````

What keeps the circuit from being closed and running?

``````a. There needs to be two motors.

b. There is no light bulb in the circuit.

-->  c. The switch is open.

d. The battery needs more capacity.
``````

In this experiment, how many batteries are there?

``````-->  a. one

b. three

c. four

d. two
``````

If the switch is closed, where would the electricity from the positive terminal go?

``````-->  a. light bulb

b. negative terminal of the battery

c. switch

d. the circuit won't run
``````

How many types of charges are shown from this battery?

``````a. one

-->  b. two

c. four

d. three
``````

Why is this circuit open?

``````a. Because the battery is weak.

b. Because the wiring is all wrong.

-->  c. Because the switch has not been closed.

d. Because the light bulb is not bright enough.
``````

How many wires are needed for this simple circuit?

``````a. 4

-->  b. 2

c. 1

d. 3
``````

Would the lightbulb work if you removed one of the wires?

``````a. it would flicker

b. it would explode

c. it would continue to light

-->  d. it would not light
``````

What does this show?

``````a. circuit diagram

-->  b. picture of a circuit

c. circuit symbols

d. circuit drawing
``````

What happens when switch or key is turned on?

``````a. Nothing happens

b. Bulb doesn't lights up

-->  c. Bulb lights up

d. All of the above
``````

How many batteries are used in this circuit?

``````a. 4

-->  b. 1

c. 2

d. 3
``````

What happens when the battery is cut off?

``````a. The lamp will get its voltage source from the switch.

b. Nothing happens.

c. The lamp will light up.

-->  d. The lamp will not light up.
``````

What will happen if you open the circuit?

``````a. the two bulbs will light

b. only one bulb will light

c. you can't open a circuit

-->  d. the bulbs will not light
``````

How many bulbs are there in this series circuit?

``````-->  a. 2

b. 3

c. 5

d. 4
``````

What would happen if the series was interrupted?

``````a. The lights would continue to work

b. The light would only work on the left

c. The circuit is closed so nothing would happen to either light

-->  d. The lights would no longer work
``````

What would happen if you removed the battery?

``````a. the lights would flash

b. the left bulb would light up

-->  c. The bulbs would turn off

d. the right bulb would dim
``````

What will happen if the battery was set on opposite direction in simple circuit?

``````a. it won't light up

-->  b. it will still light

c. it will light darker

d. it will light brighter
``````

How many light bulbs does the battery power?

``````a. 3

-->  b. 1

c. 4

d. 2
``````

What happens if the battery is removed?

``````a. The light gets dimmer

-->  b. The light turns off.

c. The light flashes

d. The light gets brighter
``````

How many volts are in the battery used in the circuit diagram?

``````a. 2

b. 1.5

-->  c. 1

d. 0.5
``````

How many lamps are shown in this image?

``````a. 4

b. 3

-->  c. 2

d. 1
``````

What circuit works?

``````a. The lamp

b. The battery

-->  c. The closed circuit

d. The open circuit
``````

How many batteries are shown in this image?

``````a. 1

b. 4

c. 3

-->  d. 2
``````

How many types of circuits are depicted in the diagram?

``````-->  a. 2

b. 1

c. 4

d. 3
``````

Other than removing one wire end from the bulb, what else can be done to change a closed circuit to open?

``````a. Move the circuit to the closet.

b. Replace the bulb with a brighter one.

-->  c. Remove the battery.

d. Change the battery to a higher capacity one.
``````

Why is it called an open circuit?

``````a. It happens when there are no arrows beside the wires.

-->  b. It is because the flow of electricity is broken.

c. It happens when the light bulb emits white light.

d. It is because the other tip of the black wire has no paste.
``````

Which of the following circuits has two or more loops?

``````a. Series Circuit

-->  b. Parallel Circuit

c. Simple Circuit

d. None
``````

How many circuits are depicted?

``````a. 4

b. 1

c. 2

-->  d. 3
``````

How many loops are in a series circuit?

``````-->  a. 1

b. 4

c. 2

d. 3
``````

If the 1st light bulb in the series is burnt, will the 2nd lamp still light?

``````a. Yes

b. dim light only

-->  d. No
``````

In which circuit will both the bulbs have the same potential difference?

``````a. SImple

b. Series

c. All 3

-->  d. Parallel
``````

How many components are present in this simple light circuit?

``````a. 2

-->  b. 3

c. 1

d. 4
``````

What happens when switch is connected to complete the circuit?

``````a. The light turns off

-->  b. the light turns on

c. Short circuit occurs

d. Nothing happens
``````

What is being discussed in this picture?

``````a. Bulb Switch

-->  b. Electric Circuits

c. Light Source

d. Energy Life
``````

In order for current to flow through a closed circuit, the circuit MUST have:

``````-->  a. A Battery

b. A Resistor

c. A Light Bulb

d. A Switch
``````

How many batteries are shown in this image?

``````-->  a. 1

b. 2

c. 4

d. 3
``````

Is battery essential for lighting a bulb?

``````-->  a. Yes

b. Maybe

c. Depends what bulb it is

d. No
``````

What type of circuit is shown in the diagram?

``````a. Simple circuit

b. Parallel circuit

c. Complex circuit

-->  d. Series circuit
``````

What will happen if the switch is turned on in the closed circuit?

``````a. circuit will be broken

b. current will not flow

-->  c. The current will flow

d. nothing
``````

In this diagram, is the switch open or closed?

``````-->  a. Closed

b. Open

c. Not enough information

d. Can't tell
``````

How many open switches are shown in this diagram?

``````a. 1

-->  b. zero

c. 2

d. 3
``````

How many switches are required for this light bulb?

``````a. four

-->  b. one

c. two

d. three
``````

In the circuit, what is directly connected to the battery's positive pole?

``````a. Negative pole

b. Switch

-->  c. Fuse

d. Light bulb
``````

How many fuses are used in this circuit?

``````a. 3

b. 2

c. 4

-->  d. 1
``````

How many bulbs are in this picture?

``````-->  a. one

b. two

c. three

d. four
``````

What is missing in the incomplete circuit?

``````a. Lightbulb

b. Switch

c. Battery

-->  d. Connection
``````

What is necessary to build a complete circuit?

``````a. light bulb and battery

b. battery and connected wires

c. light bulb and connected wires

-->  d. light bulb, battery, connected wires
``````

How many incomplete circuits are on the picture?

``````-->  a. How many incomplete circuits are on the picture?

b. 3

c. 2

d. 1
``````

How many batteries are shown in this diagram?

``````a. 4

b. 6

-->  c. 1

d. 3
``````

How many wires are used to connect the light bulb to the battery?

``````-->  a. 4

b. 3

c. 2

d. 1
``````

What type of loop is this?

``````a. Polar loop

-->  b. Closed loop

c. Seismic Loop

d. Open Loop
``````

Can the bulb light up without a battery?

``````-->  a. No

b. Sometimes

c. Intermittently

d. Yes
``````

What voltage is being used to light this bulb?

``````a. 12

-->  b. 1.5

c. 15

d. 3.5
``````

Which set of lamps is in a row?

``````a. both

-->  b. series

c. three lamps

d. parallel
``````