4-ELC-TEST

Revision points:

• know that lamps and LEDs can be used to indicate the presence of current in a circuit
• explain why a series or parallel circuit is more appropriate for particular applications including domestic lighting
• understaned that the current in a series circuit dpends on the applied voltage and the number and nature of other components
• describe the qualitative effect of changing resistance on the circuit on the current in a circuit
• recall and use the relationship between voltage current and reistance V=IR
• describe how current varies with voltage in wires, resistors, metal filament lamps and diodes and how this can be investigated experimentally
• describe the qualitative variation of resistance of LDRs with illumination and of thermistors with temperature
• use the relationship between energy transfered, current, voltage and time:

E = IVt

• recall that mains electricity is alternating current (a.c.) and understand the difference between this and the direct current (d.c.) supplied by a cell or battery

In addition, pupils will need to revise content from the third year, namely:

• Pupils understand that atoms have a neutral charge
• Pupils understand that the movement of electrons (through friction) cause insulators to gain electrostatic charge
• Pupils understand that materials can be made to have a temporary charge by induction
• Pupils understand that electrostatic charges can apply forces on one another at a distance
• Pupils can describe dangers and uses of electrostatic charge
• Pupils can identify the coulomb as the unit of charge
• Pupils can identify the Ampere as the unit of current and that it is a SI Base Unit
• Pupils can use the equation Q = It and define current as the rate of flow of charge
• Pupils can identify the direction of movement of charge in a wire, charge in an electrolyte and the direction of flow of conventional current
• Pupils can be aware of electrical hazards and how to safely wire a plug
• Pupils can use the equation P=IV to find out how the power of a light bulb changes with V
• Pupils understand that magnets exert forces on each other and other magentic materials. These forces can be magnetic attraction or repulsion
• Pupils can plot a magnetic fields patterns and understand that the direction of the arrows represents the direction of force on a test North pole
• Pupils understand that a domain is a small region of a ferromagnetic material, such as iron, nickel or cobalt, that has its own magnetic field, which can be aligned
• Pupils can recall ways to magnetise and demagnetise ferromagnetic materials
• Pupils can explain the difference between magnetically soft and hard materials
• Pupils can use the right hand grip rule to draw the magnetic field around a wire, a flat circular coil and a solenoid
• Pupils know how to make an electromagnet and how to make it stronger
• Pupils can explain that the magnetic field of an electromagnet is the result of the magnetic field around the current (in the wires) and the alignment of domains in an iron core