Mains Electricity
Gbogbo ọrọ náà
Every time you plug in a kettle, charge a phone, or switch on a lamp, you rely on a system designed to deliver energy safely. The UK mains supply provides 230 V of alternating current at 50 Hz, and understanding how that power reaches your appliance, how the wiring inside a plug is arranged, and what protects you from a fault is essential knowledge for both your exam and everyday life.
This topic takes you inside the three-pin plug, explains why fuses and circuit breakers exist, shows you how to calculate electrical power and energy transferred, and clarifies the difference between alternating and direct current. You will practise selecting the right fuse for an appliance and solving energy-transfer problems using the equations examiners expect.
Ebumnobi
- Understand how the use of insulation, double insulation, earthing, fuses and circuit breakers protects the device or user in a range of domestic appliances
- Understand why 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
- Know and use the relationship between power, current and voltage: power = current x voltage, P = I x V, and apply the relationship to the selection of appropriate fuses
- Use the relationship between energy transferred, current, voltage and time: energy transferred = current x voltage x time, E = I x V x t
- Know the difference between mains electricity being alternating current (a.c.) and direct current (d.c.) being supplied by a cell or battery
Maapụ uche
E seela isiokwu a ka ị hụ otu echiche si ejikọta.
Mepee maapụ uche na ngwa
Kaadị ncheta
Omume ncheta ngwa ngwa n'ihe a na-anwale n'isiokwu a.
Mee omume kaadị ndị a na ngwa
Akwụkwọ Ọmụmụ
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Nnyocha Ọmụmụ
Ekele diri gi maka imecha ihe karịrị na Mains Electricity. Ugbu a na ị na-enyochakwa isi echiche na echiche ndị dị mkpa, ọ bụ oge iji nwalee ihe ị ma. Ngwa a na-enye ụdị ajụjụ ọmụmụ dị iche iche emebere iji kwado nghọta gị wee nyere gị aka ịmata otú ị ghọtara ihe ndị a kụziri.
Ị ga-ahụ ngwakọta nke ụdị ajụjụ dị iche iche, gụnyere ajụjụ chọrọ ịhọrọ otu n’ime ọtụtụ azịza, ajụjụ chọrọ mkpirisi azịza, na ajụjụ ede ede. A na-arụpụta ajụjụ ọ bụla nke ọma iji nwalee akụkụ dị iche iche nke ihe ọmụma gị na nkà nke ịtụgharị uche.
Jiri akụkụ a nke nyocha ka ohere iji kụziere ihe ị matara banyere isiokwu ahụ ma chọpụta ebe ọ bụla ị nwere ike ịchọ ọmụmụ ihe ọzọ. Ekwela ka nsogbu ọ bụla ị na-eche ihu mee ka ị daa mba; kama, lee ha anya dị ka ohere maka ịzụlite onwe gị na imeziwanye.
- What colour is the live wire in a UK three-pin plug? A) Blue B) Green and yellow C) Brown D) Red Answer: C
- The UK mains electricity supply has a frequency of: A) 50 V B) 230 Hz C) 50 Hz D) 230 V Answer: C
- A 460 W appliance is connected to the 230 V mains supply. What fuse should be used? A) 1 A B) 3 A C) 5 A D) 13 A Answer: B
- Which safety device can be reset after it trips? A) Fuse B) Earth wire C) Circuit breaker D) Double insulation Answer: C
- An appliance that is double insulated does not need: A) A live wire B) A neutral wire C) A fuse D) An earth wire Answer: D
Rue ajuju ndi a n'ime ngwa ahu
Rue ajuju ndi a n'ime ngwa ahu
Akwụkwọ A Na-atụ Aro
Mụtakwuo ihe site na isi mmalite mepere emepe
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Akụkụ akwụkwọ
Electrical Safety: Systems and Devices
Electricity has two hazards. A thermal hazard occurs when there is electrical overheating. A shock hazard occurs when electric current passes through a person. Both hazards have already been discussed. Here we will concentrate on systems and devices that prevent electrical hazards. Figure 23.31 show
"College Physics: Electrical Safety: Systems and Devices" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/college-physics/pages/23-8-electrical-safety-systems-and-devices. Access for free at https://openstax.org/books/college-physics/pages/1-introduction
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Akụkụ akwụkwọ
Electric Power and Energy
Power is associated by many people with electricity. Knowing that power is the rate of energy use or energy conversion, what is the expression for electric power ? Power transmission lines might come to mind. We also think of lightbulbs in terms of their power ratings in watts. Let us compare a 25-W
"College Physics: Electric Power and Energy" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/college-physics/pages/20-4-electric-power-and-energy. Access for free at https://openstax.org/books/college-physics/pages/1-introduction
Ndị otu ndị ọzọ bipụtara ha n'okpuru ikike mepere emepe, anyị na-ekele ha dị ka ha si chọọ. Njikọ na-emepe saịtị ha.
Meecha Ajụjụ Ule Ọmarịcha
Ị chọrọ ime ajụjụ ule ọmarịcha gbasara Mains Electricity? Budata ngwa Green Bridge CBT iji nweta ajụjụ ule ọmarịcha na nyocha zuru ezu gbasara isiokwu a.
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