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12 in 1 electrical experiment set in English Manual for teachers www.magicblock.co.kr Introduction 12 in 1 electrical experiment set in English An interest of science through experiments A familiarity with science English Science context in English is easy if students learn scientific words. Students have the confidence, not only in science but also in English, which is the base of their study in school. www.magicblock.co.kr This package offers these features Features Engaging and comprehensive science content Experimental process design Practice skill for the experimental activity Final report in English The English publication makes students be familiar with science English. www.magicblock.co.kr Contents & schedule Chapter Contents Class 1 How to use this book 2 What is an atom? 3 A brief history of atomic theory 4 Periodic table of the elements 5 The basic theories of electricity 6 “12 in 1 electrical experiment set” activity guide 7 Activity 1. Static electricity 8 Activity 2. Conductors and insulators 9 Activity 3. Make a fan 5 10 Activity 4. Resistor 6 11 Activity 5. Diode 7 12 Activity 6. Make a light 13 Activity 7. Morse code machine 14 Activity 8. Light control alarm 9 15 Activity 9. Make a bell 10 16 Activity 10. Make a electromagnet 12 17 Activity 11. Make a motor 11 18 Activity 12. Solar power cell 12 www.magicblock.co.kr 1 2,3 4 8 Chapter 1. How to use this book 12 in 1 electrical experiment set in English Set up the scientific method Design procedures Study the related theories Final report Science English will be a valuable study for students to be global leaders. www.magicblock.co.kr Chapter 1. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 2. What is an atom? The smallest unit of matter is called an atom. Atom Nucleus = Proton + Neutron Electrons www.magicblock.co.kr Model of a carbon atom Chapter 2. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 3. A brief history of atomic theory 1913 : Niels Bohr (Danish physicis) Electrons move in different orbits, or energy levels, around the nucleus like planets orbit the sun. Each energy level is located a specific distance from the nucleus and contains a certain number of electrons. Current atomic model It is based on the Bohr model, except that electrons orbit the nucleus in random paths. The regions where they are most likely to be found are called "electron clouds". www.magicblock.co.kr Solar system Pluto From its discovery in 1930 until 2006, Pluto was considered the solar system's ninth planet. However, many objects similar to Pluto which orbits in irregular path were discovered in the outer solar system in the late 20th and early 21st. On August 24, 2006 the IAU (International Astronomical Union) excluded Pluto from the solar system. As result, there are 8 planets in the solar system now. www.magicblock.co.kr Chapter 3. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 4. Periodic table of the elements Periodic table Name of element Atomic symbol Atomic number Atomic mass Number of electrons In 1869, Russian chemist, Dmitri Mendeleev organized all the known elements into a chart according to their properties. www.magicblock.co.kr Periodic table www.magicblock.co.kr Chapter 4. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 5. The basic theories of electricity History of electricity Thales in BC 600 found static electricity by rubbing amber with cat's fur. English physician, William Gilbert, in 1646 made a careful study of electricity He named the electricity, in English word from [elektron] in Greek word ("of amber" or "like amber"). www.magicblock.co.kr Definition of electricity Electricity is a form of energy that can be carried by wires and is used for heating and lighting, and to provide energy for machines. www.magicblock.co.kr AC & DC AC An alternating current (AC) is an electric current whose direction reverses cyclically (+ - + -……). The usual waveform of an AC is a sine wave. It is the most efficient transmission of energy. DC Direct current (DC) is the constant flow of electric charge. It is used mostly in the circuit to work. Direct current is obtained from an alternating current through a rectifier that allow current to flow only in one direction. www.magicblock.co.kr Speed of electricity The speed of electricity is much faster because the electrons moves as below illustration. The speed of electricity in a copper conductor is about 99.9% of the speed of light. www.magicblock.co.kr Circuit Circuit is an electrical network which is an interconnection of electrical elements such as resistors, condensers, transmission lines, voltage sources, and switches. www.magicblock.co.kr Conductor / Insulator Conductor A material contains movable electric charges. Copper has a high conductivity. Insulator A material resists the flow of electric current. Materials such as PET or Teflon are very good electrical insulators. www.magicblock.co.kr Semiconductor Semiconductor is a solid material that has electrical conductivity in between a conductor and an insulator. It can vary over that wide range either permanently or dynamically by adding certain material. www.magicblock.co.kr Ohm’s law All conductors contain electric charges which will move when an electric potential difference (measured in volts) is applied across separate points on the material. The rate of current is proportional to the voltage. (Ohm's law) I = V R or V = IR I is the current, measured in amperes V is the potential difference, measured in volts R is the resistance, measured in ohms www.magicblock.co.kr Electric current Electric current is the flow of electric charges. The electric charges may be either electrons or ions. The SI unit of electric current intensity is the ampere. For an electric current of 1 ampere, 1 coulomb of electric charge (which consists of about 6.242×1018 electrons) drifts every second. I (A) = Q / T Q : the electric charge in coulombs T : the time in seconds www.magicblock.co.kr Voltage Voltage is the difference of electrical potential between two points of an electrical or electronic circuit, expressed in volts (SI unit). One volt is defined as the potential difference across a conductor when a current of one ampere dissipates one watt of power. The unit of SI is kg·m2·A-1·s-3, which can be equally represented as one joule of energy per a coulomb of charges, J/C. V = W / A = J / C = N ×m / A × s = kg × m2 / A × s3 J = N × m = kg × m2 / s2, where N is kg × m / s2 and C=A×s www.magicblock.co.kr Watt, Joule The watt (symbol: W) is the SI unit of energy, equal to one joule of energy per second. Work is done at a rate of one watt when one ampere flows through a potential difference of one volt. 1W = 1J / 1s 1W = 1A × 1V 1V = 1W / 1A = 1 J / 1A × 1s One joule is the work done by a force of one Newton moving one meter along the direction of the force. This quantity is also denoted as a Newton meter with the symbol N·m. 1J = 1N × 1m = 1kg × m2 / s2 (see Newton's second law in the chapter 17) Automobile engine : 25,000 watts (approximately 33.5 horsepower) Incandescent light bulb : 25 to 100 watts Fluorescent light : 5 to 30 watts www.magicblock.co.kr Electrical Resistance The electrical resistance R of a material is given by ; R=ρ l A R is the electrical resistance of a specimen of the material. (measured in ohms, Ω) ρ is the electrical resistivity. (measured in ohm meters, Ω·m) l is the length of the piece of material. (measured in meters, m) A is the cross-sectional area of the specimen . (measured in square meters, m²) www.magicblock.co.kr Multiple prefix for science www.magicblock.co.kr The electric shock The electric shock is happened when the current flows into your body. Your body generally has about 400-2,000ohm(Ω), 1.5V of a battery : No damage. 220V of electricity : Dangerous If AC 220V electric shock with about 400 ohm at your wet condition makes you very dangerous from below calculation ; I = V / R = 220 / 400 = 0.55A = 550mA (very dangerous to you) www.magicblock.co.kr Chapter 5. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 6. 12 in 1 electrical experiment set activity guide www.magicblock.co.kr 12 kinds electrical experiments www.magicblock.co.kr Chapter 7. Act(1) Static electricity If two things have different charges, they attract, or pull toward each other. If two things have the same charges, they repel, or push away from each other. Rubbing the plastic plate with the cloth moved electrons from the cloth to the plate. The plate had a negative static charge. The neutral tissue paper was attracted to it. When they touched, electrons slowly moved from the plastic plate to the paper. Both objects had the same negative charges, and the paper was repelled. www.magicblock.co.kr Lightning Lightning is a natural example of static discharge. The initial charge separation is thought to be associated with contact between ice particles within storm clouds. Visual phenomenon : flash Audio phenomenon : thunder The flash occurs because the air in the discharge channel is heated to such a high temperature that it emits light. The clap of thunder is the result of the shockwave created as the superheated air rapidly expands. www.magicblock.co.kr Chapter 7. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 8. Act(2) Conductors and insulators A gap exists between spring connector ① and ② and will be connected to make electricity flow in the circuit. Conductor : Make circuit to flow electricity. Insulator : Make circuit not to flow electricity. Diagram of circuit ① ② www.magicblock.co.kr My experimental test Conductor They allow electricity to pass through easily. Paperclip, cutting knife etc. Insulator Materials do not allow electricity to pass through easily. Plastic plate, paper etc. Test with other objects and fill out in the table below. www.magicblock.co.kr Chapter 8. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 9. Act(3) Make a fan (선풍기 만들기) The main component of a fan is the electric motor. The motor begins to spin under the interaction of the electric current and magnetic field inside. The fan blade attached to the motor shaft converts this spinning motion into airflow. www.magicblock.co.kr Diagram of circuit Magnetic field In physics, a magnetic field is a vector field that permeates space and which can exert a magnetic force on moving electric charges and on magnetic dipoles. The lines of magnetic field can be seen when iron filings are in the presence of a magnet. The ends of magnet have the strong magnetic force. 자석의 양 끝단이 가장 강한 자석의 세기를 가진다. www.magicblock.co.kr Fleming’s left hand rule Fleming's left hand rule for a electric motor shows the direction of the force (motion) on a conductor carrying a current in a magnetic field. The left hand is held with the thumb, index finger and middle finger mutually at right angles as left figure. The index finger represents the direction of the magnetic field. The middle finger represents the direction of the current. The thumb represents the direction of the force or motion. www.magicblock.co.kr Fleming’s right hand rule If you like to find the direction of force on the generator, you can use the Fleming's right hand rule because it is reverse process. www.magicblock.co.kr Simple DC motor STEP 1 When the coil is powered, a magnetic field is generated around the armature. The left side of the armature is pushed away from the left magnet and drawn toward the right, causing rotation. STEP 2 The armature continues to rotate. STEP 3 When the armature becomes horizontally aligned, the commutator reverses the direction of current through the coil, reversing the magnetic field. The process then repeats. www.magicblock.co.kr Chapter 9. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 10. Act(4) Resistor The fan spins faster without the resistor because a resistor "resists" the flow of electric current. The higher value of resistance (measured in ohms), the lower the current will be. Diagram of circuit www.magicblock.co.kr Series and parallel resistors Resistors in a parallel configuration, each of them has the same potential difference (voltage). To find their total equivalent resistance (R): The current through resistors in series stays the same, but the voltage across each resistor can be different. To find their total resistance: A resistor network that is a combination of parallel and series can be calculated for the total resistance: www.magicblock.co.kr Marking of resistor Four-band identification is the most commonly used color-coding scheme on resistors. The first two significant digits : the resistance value The third : a power-of-ten multiplier (number of zeroes) The fourth : the tolerance accuracy The first band (green) : a value of 5 The second band (blue) : a value of 6, and is counted as 56. The third band (yellow) : a value of 104 The end band (red) : ± 2% tolerance accuracy. It shows 560,000Ω ± 2% or 560kΩ ± 2%. www.magicblock.co.kr Chapter 10. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 11. Act(5) Diode The diode has the property allowing the current to flow only in one direction, Forward biased The current can flow through the diode from its positive side (called anode) to its negative side (called cathode). Reverse biased When the diode is connected in the opposite direction, current can't flow through and the fan does not spin. Diagram of circuit Reverse biased Forward biased www.magicblock.co.kr Diode The directionality of current flow most diodes exhibit is sometime called the rectifying property. The most common function of a diode is to allow an electric current to pass in one direction (the forward biased condition) and to block it in the opposite direction (the reverse biased condition). Polarity of diode The line mark shows the cathode of diode. www.magicblock.co.kr Why is FM radio sound clear than AM radio sound? AM radio uses Amplitude Modulation, - Use Medium Frequency (MF: 0.3MHz to 3 MHz) radio spectrum. - Transmissions are affected by interference from other sources of radio. FM radio uses Frequency Modulation, - FM is transmitted in the Very High Frequency (VHF: 30MHz to 300MHz). - FM signal is not subject to interference in the same way as AM signals. - VHF radio waves act more like light, traveling in straight lines, hence the reception range is generally limited to about 70~150kms. www.magicblock.co.kr Frequency Frequency is defined as a number of cycles, or periods, per unit time. In SI units, the unit of frequency is hertz (Hz), named after German physicist, Heinrich Hertz., 1Hz means that an event repeats once per second, 2Hz is twice per second. Heart rate and musical tempo are measured in beats per minute (bpm). Frequency of rotation is expressed as a number of revolutions per minute (rpm). The period is usually denoted as T, and is the reciprocal of the frequency f: f = 1/T www.magicblock.co.kr Chapter 11. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 12. Act(6) Make a light LED (Light Emitting Diode) is an electronic device which emits light when electric current passes through it. - It has the same property as the diode that it allows current to pass through in one direction only. - It uses much less electricity than an ordinary light bulb. - The color of the LED will depend on the type of material (semi-conductor) used to make it. Diagram of circuit www.magicblock.co.kr LED A light-emitting diode (LED) is a semiconductor diode that emits light when an electric current is applied in the forward direction of the device, -The color of the emitted light depends on the composition and condition of the semiconducting material used. - LED can be infrared, visible, or ultraviolet. - Besides lighting, interesting applications include using UV-LEDs for sterilization of water and disinfection of devices. Polarity of LED www.magicblock.co.kr Wavelength of light www.magicblock.co.kr Chapter 12. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 13. Act(7) Morse code machine In 1836, Samuel Morse demonstrated the ability of a telegraph system to transmit information over wires. - The information was sent as series of electrical signals. - Short signals are referred to as dits (represented as dots). - Long signals are referred to as dahs (represented as dashes). - With the advent of radio communications, an international version of Morse code became widely used. Typical Morse machine Diagram of circuit www.magicblock.co.kr Morse Code Characters www.magicblock.co.kr Practice of Morse code The most well-known usage of Morse code is for sending the distress signal: SOS. The SOS signal is sent as: --S ___ O --S Morse code relies on precise intervals of time between dits and dahs, between letters, and between words. Here's a chart that shows these relations. www.magicblock.co.kr Chapter 13. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 14. Act(8) Light control alarm The light sensor is an electronic component which changes its resistance with the amount of light illuminated on it. - When the light is bright, its resistance decreases and vice versa. - Many electrical appliances and lighting make use of this component to function. - For example, a street light will turn on automatically in the evening when the street gets dark. Diagram of circuit www.magicblock.co.kr Light The speed of light in a vacuum is presently defined to be exactly 299,792,458m/s (about 3×108m/s). The speed of light depends upon the nature of the medium in which it is traveling. Its speed is lower in a transparent substance than in a vacuum. - The modern theory that explains the nature of light includes the notion of "waveparticle duality" described by Albert Einstein in the early 1900s. - Einstein asserted that the energy of a photon is proportional to its frequency. - This theory states that light has both a particle nature and a wave nature. - Einstein received the Nobel Prize in 1921 for his work, "the wave-particle duality on photons". www.magicblock.co.kr Chapter 14. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 15. Act(9) Make a bell When the switch is pressed, the circuit closed and the current begins to flow through the wire around the spool (solenoid). - The metal rod gets magnetized and attracts the metal hammer arm. Due to the movement of the arm, the hammer moves and strikes the bell and the bell rings. - The movement of the arm breaks the contact and the current stops flowing. The electromagnet loses its magnetism and the arm returns back to its original position. - This completes the circuit once again and the action is repeated. As a result, the hammer vibrates and the bell continues to ring as long as the switch is pressed. www.magicblock.co.kr Diagram of bell system Diagram of circuit www.magicblock.co.kr The principle of maglev www.magicblock.co.kr Chapter 15. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 16. Act(10) Make a electromagnet An electromagnet is a type of magnet in which the magnetic field is induced by the flow of an electric current through a coil of wire. - The strength of the electromagnet depends on the amount of electric current and the number of turns of the coil. - The higher the current and the more number of turns will make the electromagnet more powerful. - The magnetic field disappears when the flow of electricity is stopped. Diagram of circuit www.magicblock.co.kr Permanent magnet and electromagnet The difference between permanent magnet and electromagnet www.magicblock.co.kr Solenoid The right hand grip rule is a physics principle applied to electric current passing through a solenoid, resulting in a magnetic field. When you wrap your right hand around the solenoid with your fingers in the direction of the conventional current, your thumb points in the direction of the magnetic north pole. (Fig. A) Electricity passing through a straight wire: The thumb points in the direction of the conventional current (from positive to negative), The other fingers point in the direction of the magnetic field from north to south.(Fig. B) Fig. A www.magicblock.co.kr Fig. B Chapter 16. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 17. Act(11) Make a motor When electric current passes through the coil (called "armature" of the motor), it becomes an electromagnet. When the red and black wires reach the stripped part of the coil, current flows, forming an electromagnet. - Since magnet pole of the same type repels each other, the north of the electromagnet is repelled by the north of the magnet. - This gives the coil a push, and it spins to a position where the wires and the coil breaks off, and the current ceases to flow. - Inertia carries it around until the stripped portion makes contact again. www.magicblock.co.kr Diagram of circuit Newton’s laws of motion Newton's laws of motion are three physical laws which provide relationships between the forces acting on a body and the motion of the body. The laws form the basis for classical physics and mechanics. - Newton’s first law (The principle of inertia) - Newton’s second law (F = ma) - Newton’s third law (action-reaction's principle) www.magicblock.co.kr Newton’s first law The term "inertia" is more properly understood as a shorthand for "the principle of inertia" as described by Newton in Newton's first law of motion, "An object that is not subject to any outside forces (friction force etc.) moves at a constant velocity.“ In even simpler terms, inertia means" A body in motion tends to remain in motion, a body at rest tends to remain at rest. www.magicblock.co.kr Newton’s second law Mass as related to "inertia" of a body can be defined also by the formula: F = ma According to this formula, the greater the mass, the less the acceleration under given force. The Newton (N) is the unit of force derived in the SI system; It is equal to the amount of force required to give a mass of one kilogram an acceleration of one meter per second squared. kg x m 1N = S2 1 N is the force of earth's gravity on an object with a mass of about 102g (1/9.8kg) (such as a small apple). 1kg on the surface of the earth weighs 9.8N. (1kg×9.8 m/s2=9.8 N) www.magicblock.co.kr Newton’s third law Whenever a particle A exerts a force on another particle B, B simultaneously exerts a force on A with the same magnitude in the opposite direction, both forces acting along the same line. This law is often simplified into the sentence, "Every action has an equal and opposite reaction.“ It is called "action-reaction's principle“. www.magicblock.co.kr Chapter 17. Science English Expression to Learn and Science English Tips www.magicblock.co.kr Chapter 18. Act(12) Solar power cell Most solar cells in the solar panels are made from a crystalline substance called silicon, one of the Earth's most common materials. Solar cells are typically made by slicing a large crystal of silicon into thin wafers and putting two separate wafers with different electrical properties together, along with wires to enable electrons to travel between layers. Diagram of circuit When sunlight hits the wafers, electrons naturally travel from one layer to the other because of the different properties of each layer, resulting in the release of electricity. www.magicblock.co.kr Photoelectric effect The photoelectric effect is a quantum electronic phenomenon in which electrons are emitted from matter after the absorption of energy from electromagnetic radiation such as x-rays or visible light. Diagram of circuit Study of the photoelectric effect led to important steps in understanding the quantum nature of light and influenced the formation of the concept of "wave-particle duality". www.magicblock.co.kr Chapter 18. Science English Expression to Learn and Science English Tips www.magicblock.co.kr