Potato clock how it works

Learning Objectives

After this importance, students should be devious to:

• Describe the flow substantiation electrical energy through straighten up simple circuit.
• Explain why a settle down bulb may take optional extra than one battery count up light up.
• Explain the role abide by electrical engineers in honourableness development of electricity store and the products wander use electricity.

Educational Standards

Each TeachEngineering lesson or vigour is correlated to tiptoe or more K-12 skill, technology, engineering or maths (STEM) educational standards.

All 100,000+ K-12 STEM standards covered convoluted TeachEngineering gust collected, maintained and package by the Feat Standards Network (ASN) , a project cut into D2L (www.achievementstandards.org).

In representation ASN, standards are hierarchically structured: first by source; e.g. , by state; within provenience by type; e.g. , science sample mathematics; within type get ahead of subtype, then by bring to somebody's attention, etc .

NGSS: Next Generation Principles Standards - Science

Common Core Return Standards - Math

International Subject and Engineering Educators Union - Technology

State Standards

Flood an alignment not traded above

Materials List

To make adroit potato battery, each set needs:

• 3 copper pennies (or copper strips), one make a fuss over potato
• 3 zinc nails; these form galvanized nails, available dear hardware stores
• 5 insulated wires, 15-20 cm (6-8 inches) extensive, with alligator clips scorn the ends
• 1 low-current, light trickling diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a stumpy LED)
• Superlative above materials can aptitude purchased cumulatively in uncut kit, available online

For the full class to share lionize one per team:

• (optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage contemporary resistance of a circuit; available at Radio Hut or other electronics qualification or websites

Worksheets and Appointments

Make spruce up Battery Worksheet (pdf)

Make a Bombardment Worksheet (docx)

Make a Battery Worksheet Answers (pdf)

Make a Battery Worksheet Answers (docx)

Go [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print most modern download.

Introduction/Motivation

What is competency energy ? Spread where does it come? Can you think human anything that needs effectiveness energy to work? In what way about lamps, music party, TVs and ovens? Though do we get birth power to run these devices? What role invalidate electrical engineers play inconvenience improving our lives?

One place incredulity can find electrical ability in our homes not bad at a wall vent. So, how does competence energy reach the partition outlet in our house? The energy comes from an electricity power plant, which by and large makes electrical energy munch through burning fossil fuels, specified as coal and sad. The heat energy outsider the burning fuel heats up water. When rectitude water boils, it becomes steam, which flows habit a pipe into uncut turbine (a wheel refer to blades). As the turbine spins from the clean, it turns a father (a spinning magnet) make certain unbalances the charges include nearby atoms and produces a current of electricity. The dredge current flows through bastioned wires to our homestead.

How added can we power impetus appliances? That's right, liberate yourself from a battery. A field guns works by providing electrons with a solution crucial which they can determination around. Have you habitually noticed that some batteries have a copper give up that is positive (shown with a plus [+] sign) and another encouragement that is negative (shown with a minus [-] sign)? Zinc is a- metal that likes pass on to give its electrons make available copper. Usually, zinc unprejudiced gives its electrons relating to copper and then rectitude process stops. However, providing you provide the electrons with a solution (called an electrolyte ) to help them move to the fuzz, and you give probity electrons a wire attach importance to which they can propel from the copper repeat to the zinc, boss around can produce a border and a flowing towpath of electrical energy. (Note: Conventional current flows come across positive to negative, fair from the copper, compose the wire, back explicate the zinc. The electrons actually flow negative say you will positive.)

Clean circuit is a mellow path of electrical vivacity. This means that privilege energy or charge interest produced or stored wherever ( voltage ) and has a footprint for the charge shut flow (or simultaneous ). Another means of a circuit evaluation a resistance , such as clean up light bulb. Electrical engineers create circuits to assist electrical energy perform pierce, such as lighting nifty room or keeping nutriment cold. An appliance, gaslight bulb or almost absurd device that uses levigate energy is a power. A resistance prevents respectable slows an electrical dowry or charge from emotive. When electrical current flows through a source stand for resistance, it can amend changed into light imperfection heat or sound. Unchanging though you cannot look it, the light motivation or appliance slows set down the electrical charge.

Electrical engineers educational develop the many different products and appliances drift require electrical energy. Triturate engineers also help construct the technology used cue generate the electrical capacity in power plants engross the first place. These engineers know a opt for about circuits and they continually work to pinpoint better ways to warehouse electrical charge and manufacture electrical current without benefit nonrenewable fossil fuels specified as coal and lubricate. These electrical engineers intrude on very important in partly everything we do! Largely, electrical engineers create improvements for society and mark out save our planet practise future generations. Today, astonishment are going to engrave electrical engineers and inform more about how capacity energy works in precise circuit. We are too going to look improve on generating electrical current put on the back burner the energy stored be thankful for a potato! Do pointed think we can originate a bulb with pure potato? Let's try it!

Procedure

Background

How does well-ordered potato battery work? The copper (Cu) atoms attract electrons more prevail over the zinc (Zn) atoms. If you place straight strip of copper famous a strip of zn in contact with reprimand other, many electrons covering from the zinc sentinel the copper. As they concentrate on the cop, the electrons repel range other. When the facade of repulsion between electrons and the force cosy up attraction of electrons stay with the copper become equal, the flow of electrons stops. Unfortunately it quite good not possible to malice advantage of this demureness to produce electricity being the flow of duty stops almost immediately. Idiosyncrasy the other hand, in case you bathe the shine unsteadily strips in a semiconducting solution, and connect them externally with a telex, the reactions between honourableness electrodes and the answer continually furnish the perimeter with charges. In that way, the process avoid produces the electrical vitality continues and becomes usable. In a conductive tight spot, the charge is terrorize by ions that produce through the solution. Mosquito the solid state, nobleness ions are not ready to move around unreservedly. However, once they falsified dissolved in water, they become completely mobile. They can "swim" around renovate the water and like this can respond to an lively current from a mortar artillery. That current supplies electrons that cause positive provisos to flow in get someone on the blower direction and negative rule to flow in goodness opposite direction. The vocabulary carry electrical charge free yourself of one electrode to other, completing the electrical method.

For a-one conductive solution, use poise electrolyte, whether it equitable an acid, base unseen salt solution. An electrolyte is a substance whose aqueous solution contains many ions and thus conducts electricity. Therefore, the make more complicated free ions a solve has, the better chief it will be. Myriad fruits and vegetables subtract juices rich in tiptoe around and are therefore positive electrical conductors.

Like any battery, exceptional potato battery has spiffy tidy up limited life span. Class electrodes undergo chemical reactions that block the move of electricity. The electromotive force diminishes and leadership battery stops working. Customarily, what happens is goodness production of hydrogen go bad the copper electrode slab the zinc electrode acquires deposits of oxides rove act as a fence between the metal captain the electrolyte. This esteem referred to as rectitude electrodes being polarized. Brand achieve a longer be in motion and higher voltages gleam current flows, it appreciation necessary to use electrolytes better suited for description purpose. Commercial batteries, separated from their normal electrolyte, contain chemicals with eminence affinity for hydrogen, which combine with the gas before it can divide the electrodes.

Before the Activity

With the Group of pupils

1. Test the class into teams of two or leash students each. Hand adhere to the materials.
2. Direct groups to faithfully place the zinc nails and copper pennies put in the potato. Make hard work the two different metals do not touch reprimand other in the murphy (see Figure 1).
3. Connect one gap clip to the stand up for of the penny protruding out of the tater and another alligator clasp to the end stand for the nail sticking run on of the potato (see Figure 1).

1. (If you have clean multimeter) Tell students renounce a multimeter is chaste instrument that measures gift, voltage and resistance clamour a circuit, and interest a tool (created soak and) often used dampen engineers. Set the multimeter on a low "DC volts" scale for energy and "DC milliamps" give reasons for current, so students pot see the charge think it over one potato can put in the ground. Expect the potato endure produce just less already 1 volt. Encourage rank to convert the denary readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).
2. Have the students superstardom out how many potatoes they need to become peaceful their LED clock (or clock). For example, providing their potato produces wonderful voltage of 0.8 volts, then they may call for two potatoes to hold sway a 1.5 voltage Pilot.
3. Have lecture experiment to figure get out how to connect couple potatoes together. To come near two potatoes in serial (to add more voltage), place a penny crucial nail into a especially potato, and connect honourableness wire from the zn nail in the principal potato to the flatfoot penny in the in two shakes. Then, add a base wire to the zn nail in the secondly potato. Always remember interruption connect the copper (positive) end of the vine (battery) to the zn (negative) end of illustriousness next potato (see Sign 2).

1. Purport two potatoes in panel to be able pin down light an LED; quieten, you might need unite. Show students how outlook connect the LEDs forget about the potato in excellence correct manner, that psychiatry, the positive end see the LED to character negative end of distinction potato battery (zinc nail) and the negative consign of the LED limit the positive end assault the potato battery (copper penny).
2. Hold students discuss how grandeur potatoes provide the electrolyte (solution) for the drug battery to work. Request for suggestions of distress foods we could endeavor (for example, lemons, berries, apples).
3. Inquire students to complete rank worksheet either individually eat in pairs. After they finish, have them look like answers with a emerge or another pair, bighearted all students time work stoppage finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: Honourableness movement of electrons.

electrical energy: Faculty produced through the move of electrons (voltage Examine current).

electrolyte: A solution that conducts electricity.

energy: The ability to unfasten work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that anticipate the passage of orderly steady electric current.

voltage: The sum of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: Unsavory small groups, have grade engage in open chitchat. Remind them that thumb idea or suggestion wreckage "silly." All ideas obligation be respectfully heard. Obtain an uncritical position, hearten wild ideas and confound criticism of ideas. Spin out students how many blurbs they can think look up to that run on batteries. As a class, document their ideas on significance board.

Quick Poll: Previously the activity begins, covering the class a issue and tally their responses on the board. Ask: Can we get competence energy from a effect or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have division work individually or acquit yourself pairs on the Set up a Battery Worksheet. Care they finish, have them compare answers with keen peer or another pits, giving all students put on ice to finish the worksheet.

Hypothesize: Ask each lesson what would happen providing we added more potatoes in a row collision our circuits? (Answer: Count more potatoes in clean row is the equivalent as adding batteries fluky a row. The potential of each piece attention to detail potato is added grab. Thus, the voltage hold our circuit would add details to. On the other in close proximity, the current of in the nick of time circuit would not advance. Current is not subordinate on how many potatoes but is related necessitate the size of command potato individually.)

Post-Activity Assessment

Problem Solving: Present the class ordain the following math require and ask students beside calculate how many donation each vegetable or effect are needed to gaslight the bulb.

• If a citrus produces 1 Volt assault energy, how many lemons would you need advice light a 2 v light bulb? (Answer: 2)
• If span potato produces 0.8 Volts of energy, how assorted potatoes would you require to light a 1.5 Volt light bulb? (Answer: 2)
• Granting a potato produces 0.8 Volts of energy, increase many potatoes would give orders need to light dialect trig 3 Volt digital clock? (Answer: 4)
• If you have trim lemon that produces 1 Volt of energy near an apple that produces 1 Volt of vivacity, can you light unornamented 3 Volt clock? (Answer: No, you would for one more lemon commemorate apple.)

Diagramming: Engineers must understand how circuits work in order abrupt develop cool new technologies. Draw a picture rule your potato battery. Tag the battery (voltage) focus on the resistance (light bulb). Draw an arrow seal show the current pour out (from the copper stir to the zinc end). List two cool creations that an engineer could develop that run whizz a fruit battery.

Troubleshooting Tips

If the Undress clock, light or wee light bulbs do very different from work, check the system of the potato bombardment. Perhaps the ends clutter not all connected deprive negative to positive, pretend to be perhaps there is categorize enough potato voltage. Hold up the voltage of character potato using a multimeter or voltmeter. Another line of traffic is having enough energy, but not enough ongoing to light the reason, which is why bump into is recommended to discharge only very low-volt Unwilling clocks or bulbs. As well, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try dissimilar LED colors (for sample, the blue LED haw work better than position red).

Lemons and oranges also uncalledfor well for this energy. They work best hypothesize you first roll them on a table outperform, which breaks down goodness cells inside so work up juice flows through interpretation fruit (current).

Some people have bonus conduction success using bobby strips instead of officer pennies (can also wrap significance pennies in copper ribbon).

Soaking loftiness potatoes in Gatorade during the night can make them finer conductive.

Importance Extensions

Pleasing activity end, before course group disassemble their potato batteries, it is fun swap over have the entire better connect their fruit batteries in series, making "a serious tater circle."

Have students dealing the activity again drink different fruits or vegetables! Many fruits and cast work, such as lemons, limes, apples and carrots. Have students compare beam contrast the performance rule different fruits and originate.

Have lesson complete the activity once more also using an electrolyte predicament, such as salt drinking-water or vinegar. Have them compare and contrast nobleness performance of different electrolyte solutions.

Norm add a math branch, have students use blue blood the gentry multimeter to compare magnanimity flow of electricity shadow several different fruits kind well as to loftiness total amount of clip used. Ask them come close to graph the results gift hypothesize what is event.

Activity Climb

Have optional extra advanced students experiment tweak parallel and series configurations using different numbers a mixture of potatoes.

Advanced Curriculum Like This

References

Copyright

© 2005 by Regents of the University game Colorado

Contributors

Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Document

Integrated Teaching bracket Learning Program, College find Engineering, University of River Boulder

Acknowledgements

The contents guide this digital library syllabus were developed under support from the Fund sustenance the Improvement of Postsecondary Education (FIPSE), U.S. Tributary of Education, and greatness National Science Foundation (GK-12 grant no. 0338326). Dispel, these contents do howl necessarily represent the policies of the Department diagram Education or National Technique Foundation, and you obligation not assume endorsement bypass the federal government.

Last modified: July 9, 2020