Electric Circuits
Resumen
Flip one switch and a whole room of lights comes on, yet unplug one fairy light and the rest stay glowing. The difference is whether the components are wired in series, one after another, or in parallel, side by side. How you connect components decides the current through each, the voltage across each, and the total resistance of the circuit.
In this lesson you will read and draw circuit diagrams, use the rule that current is the same everywhere in a series circuit, add e.m.f.s and resistances in series, use the junction rule for currents in parallel, find the combined resistance of resistors in parallel, and explain why lights at home are wired in parallel. Every calculation shows the equation, the substitution and the answer with units.
Objetivos
- Draw and interpret circuit diagrams containing cells, batteries, power supplies, generators, potential dividers, switches, resistors (fixed and variable), heaters, thermistors (NTC only), light- dependent resistors (LDRs), lamps, motors, bells, ammeters, voltmeters, magnetising coils, transformers, fuses and relays and know how these components behave in the circuit
- Know that the current at every point in a series circuit is the same
- Know how to construct and use series and parallel circuits
- Calculate the combined e.m.f. of several sources in series
- Calculate the combined resistance of two or more resistors in series
- State that, for a parallel circuit, the current from the source is larger than the current in each branch
- State that the combined resistance of two resistors in parallel is less than that of either resistor by itself
- State the advantages of connecting lamps in parallel in a lighting circuit
- [Supplement] Draw and interpret circuit diagrams containing diodes and light-emitting diodes (LEDs) and know how these components behave in the circuit
- [Supplement] Recall and use in calculations, the fact that: (a) t he sum of the currents entering a junction in a parallel circuit is equal to the sum of the currents that leave the junction (b) t he total p.d. across the components in a series circuit is equal to the sum of the individual p.d.s across each component (c) t he p.d. across an arrangement of parallel resistances is the same as the p.d. across one branch in the arrangement of the parallel resistances
- [Supplement] Explain that the sum of the currents into a junction is the same as the sum of the currents out of the junction
- [Supplement] Calculate the combined resistance of two resistors in parallel
Nota de la lección
Disponible en la aplicación Green Bridge
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Evaluación de la lección
Felicitaciones por completar la lección del Electric Circuits. Ahora que has explorado el conceptos e ideas clave, es hora de poner a prueba tus conocimientos. Esta sección ofrece una variedad de prácticas Preguntas diseñadas para reforzar su comprensión y ayudarle a evaluar su comprensión del material.
Te encontrarás con una variedad de tipos de preguntas, incluyendo preguntas de opción múltiple, preguntas de respuesta corta y preguntas de ensayo. Cada pregunta está cuidadosamente diseñada para evaluar diferentes aspectos de tu conocimiento y habilidades de pensamiento crítico.
Utiliza esta sección de evaluación como una oportunidad para reforzar tu comprensión del tema e identificar cualquier área en la que puedas necesitar un estudio adicional. No te desanimes por los desafíos que encuentres; en su lugar, míralos como oportunidades para el crecimiento y la mejora.
- In a series circuit, the current is A. largest near the battery B. the same at every point C. used up by each component D. different in each component Answer: B
- Two 1.5 V cells are connected in series the same way round. The combined e.m.f. is A. 0.75 V B. 1.5 V C. 3.0 V D. 4.5 V Answer: C
- Resistors of 3 ohm and 6 ohm in series have a combined resistance of A. 2 ohm B. 4.5 ohm C. 9 ohm D. 18 ohm Answer: C
- Resistors of 4 ohm and 12 ohm in parallel have a combined resistance of A. 3 ohm B. 8 ohm C. 16 ohm D. 48 ohm Answer: A
- Lamps in a house are wired in parallel mainly so that A. they share the current B. each can be switched independently and shines at full brightness C. they use less energy D. one failing switches them all off Answer: B
Disponible en la aplicación Green Bridge
Descarga la aplicación Green Bridge CBT en tu teléfono u ordenador para acceder a las notas completas, preguntas de práctica y más.
Disponible en la aplicación Green Bridge
Descarga la aplicación Green Bridge CBT en tu teléfono u ordenador para acceder a las notas completas, preguntas de práctica y más.
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