Btec L3

1667 words 7 pages
1. Describe the basic features of electricity at a fundamental level.

Ans: Electricity is the movement of electrons. As long as electrons in an atom are balance and revolve precisely in orbit around their sun or atom nucleus there is no electron flow or electric current in a wire. These atoms are the smallest particle into which an element can be divided without losing its property. A single atom consists of three basic components: a Proton, a Neutron and an Electron. An atom is similar to a small solar system, so is the nucleus in the centre of an atom. Protons and neutrons are contained within the nucleus. Electrons orbit around the nucleus which could be similar to planets orbiting around the sun. As an electrician I will also be
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Resistance decreases the amount of current in a circuit, because it opposes current.

6. Work out the voltage for the following arrangement of 1.5v cells.

||•|▪|▪|▪ |3v |
|•l l• •l l• |0 |
| |1.5 |
| |3 |

7. Calculate the unknown values in the following table.

|Current |Voltage |Resistance (Ω) |Power (w) |
|3I |12v |4Ω |36w |
|0.01I |5v |500Ω |0.05w |
|0.02I |54v |2700Ω |1.08w |

8. Calculate the combined resistance of the three resistors connected in series with resistance of 20Ω, 30Ω and 40Ω.