Yearly archives: 2015


resistance and ohm law

Electricity Type of currents Moving charges Ohm low Power  Resistance: Ohm´s Law   What is Electrical Resistance? When electrons flow through a bulb or another  conductor, the conductor does offers some obstruction to the current. This obstruction is called  electrical resistance. The  longer the conductor  higher the resistance. The smaller […]


moving charges

Electricity Type of currents Moving charges Ohm low Power  Electricity: Moving charges   ENERGY CHANGES IN A SIMPLE ELECTRIC CIRCUIT When current flows in a conductor, heat energy is given out at every point in that conductor. This energy comes from the battery (or other source, e.g. a generator) that […]


types of currents

Electricity Type of currents Moving charges Ohm low Power  Types of currents. ac/dc    What does it mean: ac/dc? Ok, apart from a rock group? There’re  two types of current, defined based on  the directions of the movement of the  electrons. An electric current is called a direct current (d.c.) […]


electricity

Electricity Type of currents Moving charges Ohm low Power  Let’s Explore Electricity!. The movement of the electron   Electricity is the most widely used form of energy. Electricity  run our fridges, washing machines and in general, all electrical  appliances in the kitchen. Electricity will probably power all future cars’ motor. […]


Injection Molding

Injection Molding .   Video text. Read carefully the text and watch the Video about this Method of Processing Plastic. Injection molding is the most common method of producing parts out of plastic material. The process involves injecting molten plastic at high pressure into a mold shaped in the form […]


Plastics videos and Exercises

Plastics Fabrication Adhesives Exercises  Plastics, videos  and Exercises .     Below, we are going to see a series of questions for the 3º ESO technology students. All of the questions can be completed interactively in the part of “potatoes”. Choose the correct answer 1. Plastics are: a) Elastomers which […]


Adhesives and assembly in plastics

Plastics Fabrication Adhesives Exercises  Adhesives and assembly in plastics.   Adhesives There are many adhesives (glues) available that have been developed over recent years. Some adhesives, such as wood glues, are for specific materials, whilst others, like epoxy resin, will bond dissimilar materials. Adhesives may be rigid or they may […]


Fabrication of Plastics

Plastics Fabrication Adhesives Exercises  Fabrication of Plastics.   Fig 1 Extrusion: Using this processing it is possible to produce a wide range of different forms of plastic, such as tubes, sheets and films, structural parts, etc. 1º Step: Plastic pellets are placed in a feed hopper which feeds into the […]


Plastics

Plastics Fabrication Adhesives Exercises  Most plastics are made from oil. Plastics are man-made materials. They are a useful invention because they are waterproof, easy to shape and tough. They have taken the place of traditional materials like wood and metal in many products. It is bad to waste plastic, as […]


Structure exercises

Structure exercises Posted on November  14th, 2009 by Technology Department    STRUCTURES TYPES OF FORCES THAT ACT ON A STRUCTURE 1º Fill in the blanks in these statements. (a) The two main kinds of structures are _______ and _______ structure. (b) If a frame structure has no ‘skin’ on it, […]