Electrical Quantities (continued)
Gbogbo ọrọ náà
Every time you switch on a light, charge is pushed around a circuit by a source, gives up energy in the bulb, and returns for more. The push is the electromotive force, the energy given up per coulomb is the potential difference, and the opposition to the flow is the resistance. Master these three and you can analyse and cost almost any circuit.
In this topic you will define e.m.f. and potential difference, use voltmeters, measure and calculate resistance, and link power and energy to current and voltage. You will sketch the current-voltage graphs of a resistor, a lamp and a diode, and learn to work out the cost of running appliances in kilowatt-hours.
Ebumnobi
- Define electromotive force (e.m.f.) as the electrical work done by a source in moving a unit charge around a complete circuit
- Know that e.m.f. is measured in volts (V)
- Define potential difference (p.d.) as the work done by a unit charge passing through a component
- Know that the p.d. between two points is measured in volts (V)
- Describe the use of voltmeters (analogue and digital) with different ranges
- Recall and use the equation for resistance V R = I
- Describe an experiment to determine resistance using a voltmeter and an ammeter and do the appropriate calculations
- State, qualitatively, the relationship of the resistance of a metallic wire to its length and to its cross-sectional area
- Understand that electric circuits transfer energy from a source of electrical energy, such as an electrical cell or mains supply, to the circuit components and then into the surroundings
- Recall and use the equation for electrical power P = IV
- Recall and use the equation for electrical energy E = IVt
- Define the kilowatt-hour (kW h) and calculate the cost of using electrical appliances where the energy unit is the kW h
- [Supplement] Recall and use the equation for e.m.f. W E = Q
- [Supplement] Recall and use the equation for p.d. W V = Q
- [Supplement] Sketch and explain the current-voltage graphs for a resistor of constant resistance, a filament lamp and a diode
- [Supplement] Recall and use the following relationship for a metallic electrical conductor: (a) resistance is directly proportional to length (b) r esistance is inversely proportional to cross-sectional area
Nkuzi Olu
Gee ntị na nkuzi a na ngwa
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
Ndetu Nkuzi Zuru Ezu di na Ngwa Green Bridge
Nweta ngwa Green Bridge CBT na ekwenti gi ma o bu kompiuta maka ulo akwukwo IGCSE zuru oke: akwukwo ule ndi gara aga, usoro nyocha, eserese uche, kaadi omumu na nkuzi olu.
Nnyocha Ọmụmụ
Ekele diri gi maka imecha ihe karịrị na Electrical Quantities (continued). 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.
- The resistance of a component carrying 2 A with 12 V across it is: A. 24 ohm B. 6 ohm C. 0.17 ohm D. 10 ohm Answer: B
- A voltmeter should be connected: A. in series with the component B. in parallel with the component C. before the cell only D. it does not matter Answer: B
- The I-V graph of a resistor of constant resistance is: A. a curve flattening off B. a straight line through the origin C. zero one way only D. a horizontal line Answer: B
- A 60 W lamp runs for 1 hour. The energy used is: A. 60 J B. 0.06 kW h C. 60 kW h D. 3600 kW h Answer: B
- 1 kilowatt-hour is equal to: A. 1000 J B. 3600 J C. 3.6 MJ D. 60 J Answer: C
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
Ohm's law
Describe how current is related to charge and time, and distinguish between direct current and alternating current
"Physics: Ohm's law" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/physics/pages/19-1-ohms-law. Access for free at https://openstax.org/books/physics/pages/1-introduction
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Akụkụ akwụkwọ
Electric Power
Define electric power and describe the electric power equation
"Physics: Electric Power" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/physics/pages/19-4-electric-power. Access for free at https://openstax.org/books/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 Electrical Quantities (continued)? Budata ngwa Green Bridge CBT iji nweta ajụjụ ule ọmarịcha na nyocha zuru ezu gbasara isiokwu a.
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