physics Flashcards
Define static electricity and dynamic electricity and describe electric charge
Static electricity is when the electrons build up in one space and are not allowed to move (static= not moving). Opposite charges attract (negative and positive), like charges repel (negative and negative, positive and positive)
Dynamic electricity is the flow of electric charges through a conductor; in other words, an electric current.
Electric charge: Electricity is a form of energy caused by a movement of electrons.
Electrons have a property called ‘electric charge’ which refers to a force when near other electrically charged matter.
Electric charge can be both positive and negative.
Describe how matter can be charged by friction or by induction
When two different insulating materials are rubbed, electrons get transferred from one body to another. This method is known as charging by friction. For example, when a plastic rod is rubbed with a piece of cloth, electrons are transferred from the rod to the cloth.
The charging by induction process is where the charged particle is held near an uncharged conductive material that is grounded on a neutrally charged material. The charge flows between two objects and the uncharged conductive material develops a charge with opposite polarity.
Be able to define and explain the difference between conductors and insulators based on flow of electric charge
Electrical conductors are materials which electrons flows through easily. They are usually metals due to the presence of free electrons allowing for easy electron flow. Liquids with free moving ions can conduct electricity.
Electrical insulators are materials which do not allow electricity to flow easily. Materials in which electrons are “held tightly” to the atom (no free electrons) E.g liquids with no ions, like oil, won’t conduct
Understanding of the different components of an electric circuit
Electric circuit is a path that transmit electricity, and consists of 3 essential items: power supply to provide electrical energy, load (or loads) in which electrical energy is converted into other useful forms of energy (e.g light, heat, sound) and a conducting path that allows electric charge to flow around the circuit.
Ability to draw and construct appropriate circuit diagrams using the correct symbols
Differentiate between series and parallel circuits and understand how current, voltage and resistance are affected in series and parallel circuits
Series: All components of the circuit are connected one after the other to form a single loop. (There is only one path for the electron to flow). Components have the same current flowing through them but split the voltage between them. In a series circuit, adding more resistance increases total resistance. Total resistance for a Series circuit: Total resistance ®= R1+R2 Conclusion: same current diff voltage
Parallel: Have a number of branching circuits, with each brand having its own components. The current leaving the battery is split between each branch/path. Electrons flowing through the battery get full push from the cell- they do not share it like in a series circuit. IIn a parallel circuit, adding more resistance decreases total resistance. Total resistance ®: 1/Rt=1/r1+1/R2 Conclusion: diff current same voltage
Define and measure current and voltage
Current: flow of electrons along a conducting path, measured in amperes or amp for short. using ammeters
Voltage: is the amount of energy pushing electrons in the circuit. Measured in volts (v) using a voltmeter
Resistance: resists the flow of electrons, does not allow current to flow through easily
Understand Ohm’s Law (V = IR) and manipulate Ohm’s Law to determine voltage, current and resistance in series and parallel circuits
ΔV = the electric potential difference between two points on a circuit
I = the current between those two points
R = the total resistance of all electrical devices present between those two points
Describe how an electromagnet is used to generate magnetic field lines within a coil
Opposites attract, likes repel, magnetic thingies go out and it goes from the north to the south, goes at the top and bottom
Differentiate between the forms of heat energy - Conduction, Radiation & Convection
