Y3H_CH5_§5.1

• Natuurkunde / Scheikunde
• Middelbare school
• havo
• Leerjaar 3

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Circuits

What do you need to bring to this lesson: (standard for every lesson!)

• your textbook (book 3B)
• a notebook (preferably squares, lines is okay too, don't buy a new one just for squares)
• a pen
• a pencil
• a ruler/triangle
• a calculator
• a computer (charged up)

Y3H_CH5_LSN1

Circuits

CHAPTER 5

CIRCUITS

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Circuits

What do you remember?

• You know the symbols that you use to make a circuit diagram.
• You can list some applications of infrared radiation.
• You can explain what voltages and currents are and how you measure these variables.
• You can explain the difference between a parallel circuit and a series circuit. 

WIRE

SWITCH

LAMP

POWER SOURCE

BATTERY

MOTOR

VOLT METER

AMMETER

LED

BELL

Name 3 uses for infrared radiation:

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Infrared radiation:

Infrared (IR) radiation is invisible light felt as heat, commonly used for, remote controls, heating, and thermal imaging. It enables wireless communication, warms spaces, cooks food, and allows cameras to detect heat signatures for security.

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Possible examples are:

• Remote Controls: TVs, air conditioners, and other appliances use IR light to transmit short-range, line-of-sight signals.
• Heating (IR Lamps/Panels): Used in electric heaters, saunas, and food warmers (like restaurant heat lamps) to provide direct, efficient heat.
• Thermal Imaging & Night Vision: Cameras detect heat signatures from people or objects, allowing security, firefighting, and military tools to "see" in total darkness.
• Medical & Health Therapies: IR lamps are used to soothe muscle tension, improve blood circulation, and treat joint pain.
• Non-Contact Thermometers: Used to measure surface temperatures instantly, such as ear or forehead thermometers.
• Industrial Curing: Used to quickly dry paint, coatings, or plastics in manufacturing.
• Data Transmission: Used in fiber optic cables for high-speed internet and occasionally in short-range wireless data transfer.
• Astronomy: Telescopes use infrared to see through cosmic dust and observe cool stars, planets, and galaxies.

Stays the same over a series circuit.

Stays the same over a parallel circuit.

voltage

current

Is divided over various parts of a parallel circuit.

Is divided over items in a series circuit.

Moves over a wire.

Moves through a wire.

unit is volts (V)

unit is amps (A)

voltage is the same for all components

current is the same throughout circuit

Series

Parallel

Still works if one lamp is broken

If you connect batteries this way, you can add their voltages

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Lesson 1 §5.1

Charge & voltage

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LEARNING OBJECTIVES:

• You can describe how you can give an electrically neutral object made of perspex or PVC and electric charge.
• You can explain how to tell the difference between a positive charge and a negative charge.
• You can explain what role electrons play when an object is charged and discharged.
• You can describe two ways of discharging an object that has been charged.
• You can explain what voltage sources are used in daily life. 

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Charge and voltage:

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Charge and voltage:

• Objects can be electrically charged (static). Electrons move from one object to another

• Positive charge: electrons < protons
• Negative charge: electrons > protons
• Neutral: electrons = protons

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Attracting and repelling:

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Voltage:

Voltage is the difference in charge between two objects.

• If you connect the object with a wire you will get electricity
• Electrons flow from negative to positive

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Current:

Electrical current - the amount of charge (electrons) flowing through the wire per second

• Electricity = the movement of electrons

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To be completed by next lesson:

• review your notes
• study the glossaries

To be completed by next week:

• Complete ex 1abd, 2, 3, 5, 6 on pages 71 & 72
• Read textbook pages 75-78