Science - Circuits and Conductors Day 4

Circuits and Conductors
Day 4

ELECTRICITY

Multiple Choice

A student has been charging her laptop and notices that one of the wires on the charger has become worn, and the metal wire inside is showing. She knows that this is a dangerous situation, and tells her teacher. The teacher sees the problem, and decides to unplug the laptop. Which of the following objects would be the safest way for the teacher to handle the plug?

• a metal fork

• his bare hands

• thick rubber gloves

• thick tin foil gloves

​Materials That Conduct Electricity

​Electricity is a form of energy that can be transformed, or changed, into other forms of energy including heat, light, sound, and the energy of motion, or mechanical energy. We use electricity every day in each of these forms. Electricity can be transformed into heat to cook our food. It can be transformed into light so that we can see inside building like homes and schools. Electricity can be transformed into sound so we can listen to our favorite music. Electricity can be transformed into mechanical energy to run fans and air conditioners to keep us cool, and pencil sharpeners to keep our pencils sharp.

Multiple Choice

Current electricity flows through

• wires
• string
• rubber
• plastic

Multiple Choice

The circuit onthe right is

• open
• closed

Multiple Choice

How does a switch work?

• It opens and closes the circuit
• It makes the light bulb brighter
• It is a resistor

Multiple Choice

Electric charges that are alike _______ each other.

• Attract

• Repel

Multiple Choice

Which of the following is an insulator?

• copper

• wood

• silver

• salt water

Multiple Choice

The girl's hair and the comb are attracting one another. The hair and the comb have

• opposite charges

• like charges

Multiple Choice

Copper is used in wiring because it is an excellent______________ of electricity.

• circuit breaker
• conductor
• insulator
• fuse

Multiple Choice

I am the path along which electricity travels.

• electric circuit
• conductor
• insulator
• fuse

​All of this electricity that we use comes from a generator at a power plant. Power plants produce electricity, and send it to homes, businesses, and schools through power lines, like those in this picture. For those power lines to conduct, or carry, electricity, they must be made of a material that allows electricity to flow through them. Most metals conduct electricity well. Gold is a metal that conducts electricity, but it is far too expensive to use for power lines like these. Very small amounts of gold are used as conductors in some computer parts. Copper is the most common metal used as a conductor in wire.

Multiple Choice

Generators generate

• electricity

• mechanical energy

• heat

• chemical energy

Multiple Choice

The area surrounding a magnet that applies a force without touching the object.

• magnetism

• magnet

• magnetic theory

• magnetic field

Multiple Choice

Like poles of a magnet

• attract

• repel

Multiple Select

An electromagnet includes

• heat

• insulators

• magnetism

• electricity

​Some materials conduct electricity. To conduct means to move, or to allow to move freely. These materials allow electricity to flow freely through them.

Multiple Choice

Is Iron a Conductor or Insulator?

• Conductor
• Insulator

Multiple Choice

Which is NOT an insulator.

• Wool
• Plastic
• Copper
• Glass

Multiple Choice

Is Wood a conductor or Insulator?

• Conductor
• Insulator

Multiple Choice

What is the difference between a conductor and an insulator?

• An insulator allows electricity to flow through it easily and a conductor does not
• A conductor allows electricity to flow through it easily and an insulator does not.
• An insulator is magnetic and a conductor is not
• A conductor is magnetic and an insulator is not

Multiple Choice

A great conductor of energy is:

• wood
• plastic
• metal
• cloth

Multiple Choice

All of the following are conductors except _______.

• metal spoon
• wire
• iron nail
• plastic spoon

Multiple Choice

What object would best complete this circuit?

• A battery
• a peice of yarn
• an insulator
• a conductor

Multiple Choice

The plastic covering is there to:

• Provide a conductor for electrical energy to flow.
• Provide an insulator so that electrical energy will not pass outside of the wires.
• Provide a conductor so that electrical energy can NOT flow.
• Provide an insulator so that electrical energy can flow.

​Some materials do not allow electrical energy to flow through them. These materials are called insulators. Rubber is commonly used as an insulator on wires. In this picture, three strands of copper wire are used in an electrical circuit. The black wire and the white wire are used to conduct, or move, electricity through a circuit. The bare copper wire in the middle is used as a safety wire. It is connected to the third prong on a plug. It carries electricity outside to a metal pole sunk in the ground. It is called a ground wire for this reason. The black wire and the white wire are covered in rubber to prevent electricity flowing directly between the two wires before they complete a circuit. If electricity flowed between these two wires before they completed a circuit, this would create a short circuit. Short circuits are dangerous, and can cause fires. The paper in the middle of the three wires just keeps them in order.

Multiple Choice

Another word for conduct is _________________________.

• create

• stop

• move

• inspire

Multiple Choice

If electricity flowed between two wires before they completed a circuit, this would create a ____________.

• complete circuit

• short circuit

• simple circuit

• parallel circuit

Here you can see the same wire connected to a wall outlet (the other end of this wire is not connected to anything). When you plug in a stove, a light, a speaker, or a fan, electricity can flow through this circuit to be transformed in to heat, light, sound, and mechanical energy.​

Multiple Choice

Materials that do not conduct electricity are called insulators. A student is using the paper circuit shown below. She has decided to close the circuit so that the light is on. She has discovered that closing the circuit with an insulator between the tape and the battery will keep the bulb off, until the insulator is pulled out. Which of the following materials will work as an insulator that the student can put in her circuit to keep the light off until the insulator is pulled out?

• a strip of tin foil

• a copper wire

• a strip of paper

• a paperclip