2.20 describe experiments to investigate how insulating materials can be charged by friction Experiment: To investigate how insulating materials can be charged by friction Apparatus: Glass rod, silk cloth, electroscope Procedure: Take a glass rod and silk cloth. Rub...
2.12 describe the qualitative variation of resistance of LDRs with illumination and of thermistors with temperature An LDR is a light dependant resistor. Its resistance changes with the intensity of light. It has a high resistance in the dark but low in the light. A...
2.13 know that lamps and LEDs can be used to indicate the presence of a current in a circuit All lamp and LEDs emit light when current passes through them. If an LED or a lamp lights up when connected to a circuit, this shows that a current is present in the circuit.
2.14 know and use the relationship between voltage, current and resistance voltage = current × resistance V = I × R
2.15 understand that current is the rate of flow of charge The size of an electric current indicates the rate at which charge flows. Charge(Q) is measured in coulombs (C). Current is measured in amperes (A). If 1 C of charge flows along a wire every second the current...
2.16 know and use the relationship between charge, current and time charge = current × time Q = I × t
2.17 know that electric current in solid metallic conductors is a flow of negatively charged electrons Current is the flow of charge. One coulomb of charge is equivalent of the charge carried by approximately six million, million, million (6 x 1018) negative electrons.
2.18 understand that voltage is the energy transferred per unit charge passed the volt is a joule per coulomb.
2.25 explain some uses of electrostatic charges, eg in photocopiers and inkjet printers Electrostatic charges can be used in electrostatic paint spraying, inkjet printers, photocopiers, electrostatic precipitators etc. In inject printers inks are given negative...
2.24 explain the potential dangers of electrostatic charges, eg when fuelling aircraft and tankers In some situations the presence of static electricity can be a disadvantage. As aircraft fly through the air, they can become charged with static electricity. As the...
2.23 explain electrostatic phenomena in terms of the movement of electrons An electrostatic phenomenon is an event where electricity has a special effect, for example a static shock. Electrons move from one material to another. Materials with a negative charge will...
2.22 understand that there are forces of attraction between unlike charges and forces of repulsion between like charges Similar charges repel each other and unlike charges attract each other. The attraction and repulsion occurs because of electrostatic force.
2.21 explain that positive and negative electrostatic charges are produced on materials by the loss and gain of electrons If two material are rubbed together electrons will be transferred. The one that gains electrons will be negatively charged and the one that losses...
2.5 know and use the relationship power = current × voltage P = I × V and apply the relationship to the selection of appropriate fuses Power is amount that represents how much voltage or energy is converted every second. It is calculated using this equation: Power, P...
2.19 identify common materials which are electrical conductors or insulators, including metals and plastics Conductors: Electrical conductors are materials that allow current to pass through them. Conductors have free electron diffusion to pass current. Metals like...
2.4 understand that a current in a resistor results in the electrical transfer of energy and an increase in temperature, and how this can be used in a variety of domestic contexts Normal wiring in the house are said to have low resistance and the current pass through...
2.3 understand the uses of insulation, double insulation, earthing, fuses and circuit breakers in a range of domestic appliances Insulation: Some appliances are cased with insulators like plastic rather than metal to prevent user from receiving shock. This casing is...
2.2 understand and identify the hazards of electricity including frayed cables, long cables, damaged plugs, water around sockets, and pushing metal objects into sockets Electricity is very useful, but it can be dangerous if it is not used safely. Broken plugs and...
2.7 understand the difference between mains electricity being alternating current (a.c.) and direct current (d.c.) being supplied by a cell or battery. The mains electricity supply provides alternating current (a.c.). Alternating current constantly changes their...
2.6 use the relationship between energy transferred, current, voltage and time energy transferred = current × voltage × time E = I × V × t The power of an appliance (P) tells you how much energy it converts each second. This means that the total energy (E) converted...
2.1 use the following units: ampere (A), coulomb (C), joule (J), ohm (Ω), second (s), volt (V), watt (W). Unit of current: ampere (A) Unit of charge: coulomb (C) Unit of energy: Joule (J) Unit of resistance: ohm (Ω) Unit of time: second (s) Unit of voltage or...
2.11 describe the qualitative effect of changing resistance on the current in a circuit Resistance is inversely proportional to current. Higher resistance means lower current and higher current means lower resistance. In other words resistance is the opposite of...
2.10 describe how current varies with voltage in wires, resistors, metal filament lamps and diodes, and how this can be investigated experimentally In parallel circuit, current varies with the resistance and voltage. Voltage are same at all branches. This circuit...
2.9 understand that the current in a series circuit depends on the applied voltage and the number and nature of other components In a series circuit the current is the same in all parts. Current is not used up as it passes around a circuit. The size of the current is...
2.8 explain why a series or parallel circuit is more appropriate for particular applications, including domestic lighting Series Circuit: one switch can turn off the components on and off together if one bulb ( or other component) breaks, it causes a gap in the...