All 4th Grade Science Resources
Example Questions
Example Question #191 : 4th Grade Science
Which object is an example of a device that converts electrical currents into heat energy?
A freezer
A candle
The Sun
A toaster
A toaster
A toaster is an example of how a device can convert electrical currents into heat energy. The toaster is plugged into the electrical outlet and electricity flows through the cord and into the heating elements of the toaster. The toaster than warms and crisps the food item placed inside. The heating coils warm the bread as a result of electrical currents being transferred.
Example Question #192 : 4th Grade Science
Which answer choice is an example of how electrical currents in nature transfer energy?
Television sets
Power plants
Lightbulbs
Lightning
Lightning
Lightning is a powerful example of electricity in nature. During a thunderstorm, many small bits of ice bump into each other as they move around in the air in the clouds. These collisions create an electric charge. The cloud fills up with electrical charges. The positive charges or protons form at the top of the cloud, and the negative charges or electrons form at the bottom of the cloud. The ground beneath the cloud creates a positive charge. The charge coming up from points on the ground (like treetops or buildings) eventually connects with a charge reaching down from the clouds and lightning strikes.
Example Question #193 : 4th Grade Science
Juan is trying to build a device to transfer energy through electrical currents and needs to use a conductor to allow the electrons to flow easily. Which material should he choose to use in his design?
Plastic
Rubber
Wood
Copper
Copper
Juan should use copper if he is looking for something that is a good conductor. A conductor is a material that transmits energy. Electrons can flow easily through a conductor. If he chooses the rubber, wood, or plastic, those items are insulators and would prevent the flow of energy because electrons cannot flow easily through an insulator. Electricity is the flow of electrons – tiny negatively charged particles in atoms, so their flow mustn't be hindered.
Example Question #194 : 4th Grade Science
Energy cannot be transferred from place to place by electric currents.
False
True
False
Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy can also be transferred from site to site by electric currents; the currents may have been produced, to begin with by transforming the energy of motion into electrical energy. The statement presented is false because electrical currents can transfer energy.
Example Question #195 : 4th Grade Science
Jamarious wants to transfer energy by electrical current for a class project. He begins observing simple household examples of electrical currents moving energy. Which answer choice is NOT an example of energy transferring through electricity?
Using an air conditioner to cool the house down in the summer
Lighting a candle when the power goes out to provide light
Pre-heating the oven to bake fresh cookies
The doorbell ringing through the house from the front porch
Lighting a candle when the power goes out to provide light
All of thee examples except for one demonstrate electricity or electrical currents transferring energy in a simple household scenario. Lighting a candle when the power goes out to provide light does not use electricity or an electrical current, so it is the non-example. A candle does produce light and heat energy, but it is through a chemical reaction with the match lighting the wick. All of the other examples are creating a change using electricity.
Example Question #6 : Observe How Energy Is Transferred By Electric Currents
Why is it important to have a good conductor when trying to transfer energy through electrical currents?
Conductors transmit energy so electrons can flow easily
Conductors are not necessary when trying to transfer energy through electrical currents
Conductors block the electrons from traveling so the electricity can build-up
Conductors tell electrons what to do so they can create electricity
Conductors transmit energy so electrons can flow easily
Because electricity is the flow of electrons, or negatively charged particles in atoms, conductors are necessary when trying to transfer energy through electrical currents. Conductors allow electrons to flow easily, which in turn transmits energy. Someone would not want to block electrons from traveling whatsoever when trying to create an electrical current - materials that do this would be called insulators.
Example Question #7 : Observe How Energy Is Transferred By Electric Currents
True or false: Insulators assist in the transfer of energy through electrical currents.
True
False
False
Insulators slow down the flow of electrons, which prevents the transfer of energy through electrical currents. For electrical currents to function correctly, the negatively charged particles must be able to flow easily. A conductor would assist in the transfer of energy through electrical currents, while insulators stop it from happening.
Example Question #1 : Observe How Energy Is Transferred By Electric Currents
Cho wants to observe the transfer of energy through electrical currents at her school. She observes in a few of her classrooms and notices several different energy transfers. Which of the following is an example of an electrical transfer of energy?
The groundskeeper throwing a broomstick
The overhead lightbulb in the greenhouse turned on
A cauldron bubbling over a fire
A professor walking the halls with a candle
The overhead lightbulb in the greenhouse turned on
These responses show a number of different energy transfers. A bubbling cauldron would be an example of a transfer of heat energy. A professor walking the halls with a candle is an example of light energy at work. The thrown broomstick depicts kinetic energy. The lightbulb turning on is an example of a transfer of electrical energy, because electricity causes the wire in the bulb to glow.
Example Question #8 : Observe How Energy Is Transferred By Electric Currents
True or false: Electrical and heat energy transfers follow the same process.
False
True
False
Heat travels through convection, conduction, and radiation. While both heat energy transfers and electrical energy transfers require good conductors, in a heat energy transfer, the particles begin vibrating and bumping into one another more and more quickly, spreading heat. Electrical currents require electrons to travel through wires or a reaction between positive and negatively charged particles.
Example Question #9 : Observe How Energy Is Transferred By Electric Currents
True or false: Electrons are negatively charged particles.
True
False
True
Electrons are negatively charged particles, while protons are positively charged. Electrons are the primary carriers of electricity in solid objects.