Unit 2 Electricity Flashcards
What are the two types of circuits?
Series and Parallel
What is a series circuit?
A series circuit is a type of circuit where there is a single loop. One switch turns on or off all of the bulbs in the circuit. And there is an equal amount of current flowing through the whole circuit.
What is a parallel circuit?
A parallel circuit is a type of circuit where there are paths that branch out so that the current can divide and flow through any branch.
When is a series circuit appropriate and why?
A series circuit would be appropriate for decorative lighting as all of the lights don’t need that much voltage. The energy source in a circuit is evenly distributed throughout all of the bulbs in the circuit. In which the decorative lights still get enough voltage to serve their purpose. Although if one bulb were to break, it would disrupt the flow of current through the whole series causing all the lights to turn off.
When is a parallel circuit appropriate and why?
An appropriate place to use a parallel circuit would be in the light systems of our homes. As different lights in different rooms can be the different branches. Parallel circuits would be suitable in this scenario as you can confidently control which lights are on in different rooms. You can individually decide with switches which lights are on and off in different branches. You can block the current in one branch, as the current would just flow a different path with the other lights still on. Different branches can have different voltages.
How does current flow in a series circuit?
The current is the same throughout. Evenly distributed by the energy sources. If there were double the amount of cells, there would be double the amount of voltage/current.
How does current flow through a parallel circuit?
There can be different amounts of current in different branches of the circuit. But the number of electrons flowing into the junction must be equal to the number of electrons that leave the junction each section.
How do we know if current is flowing through the circuit?
If the lamp or LED is successfully on, we know that current is flowing through the circuit as it provides power to the light source. Therefore lamps and LEDs can be used as a indicator for the presence of current in a circuit.
What is the unit and symbol for charge?
Q = charge
C = coulombs
What is charge?
measure of total current that flowed within a certain period of time
What is the formula for charge?
Q (C) = I (A) * t (s)
I is the current
What is equal to the flow of negative charged electrons?
Electric current in solid metallic conductors
Why is current conserved at a junction?
Total current entering the junction = total current leaving the junction. Therefore in a circuit no charge can be created nor destroyed (law of conservation of mass) but can be transferred.
How can you have protection in domestic appliances?
insulation, double insulation, earthing, fuses and circuit breakers
How does insulation protect against domestic appliances?
prevents electric shock by creating a barrier between live components and surroundings
How does double insulation protect against domestic appliances?
gives an extra layer of protection, therefore you don’t need an earth wire
How does earthing protect against domestic appliances?
safely directs excess current to the group preventing electric shock
How does fuses protect against domestic appliances?
breaks the circuit when current exceeds a safe level, preventing fires
How does circuit breakers protect against domestic appliances?
automatically interrupt circuits when excess current comes
What do current in resistors produce and what are they useful for?
electric current in resistors produce heat energy - which is why they are used in electric heaters and stoves to generate warmth for cooking
