Electrical Principles Unit Review Flashcards
What charges objects that attract each other have?
Opposite charges attract
what form of energy, that energy in batteries is stored as?
Energy in batteries is stored as chemical energy
What is the definition of current electricity?
Current electricity is the steady flow of charged particles (electrons)
Give an example used to describe the behavior of current electricity.
Water flowing down a river would be used to model current electricity
What unit we use to measure the energy used by an electrical device?
Energy used by an electrical device is measured in Joules
How do you calculate total energy consumed?
E = P (Watts) x t (seconds)
What main environmental problem is created by industrial production of carbon dioxide in large amounts?
Global Warming or climate change
What is the energy transformation in a fuel cell?
Chemical to electrical
How can we improve efficiency in fridges?
Add insulation and tighten the door seals. Make sure the motor is well oiled.
How do you calculate output energy when given the efficiency of the machine and the input energy to make it work?
Output energy = % efficiency/100 x Joules input
What does the efficiency rating of a machine tells you?
Tells you how much of the energy the machine converts to useable output energy. If a machine is 60% efficient, it converts 60% of the energy into useable output energy…the other 40% is lost.
What are some examples of renewable and non-renewable resources?
Oil and gas non –renewable…water, trees are renewable
What two things interact to make an electrical motor work?
Magnets and electromagnets interact to make a motor work
Look at a scenario and identify what energy conversions are happening. Example: if I put a battery in my radio to make it run, then energy conversion happening is chemical to electrical (sometimes there can be more than two conversions happening)
Batteries and energy in our bodies start as chemical energy
Look at a picture of a circuit and identify what bulb(s) will light up when certain switches are closed or opened.
We did an example on the board
Look at a picture of a circuit and identify if it is a series or parallel circuit.
Series circuit has all loads in one single loop and electricity can only flow in one path
What example of a water tower and pipe would represent the biggest voltage and current?
A high water tower with a wider pipe would have the highest voltage and current
What is the advantage of a parallel circuit over a series circuit?
A parallel circuit will still work if a load stops working
How do identify examples of energy output and input. Answers will either be mechanical, chemical, thermal, and electrical.
Example: A heater has thermal output energy
Know how to calculate voltage of an object when given amperage and resistance.
V = I x R (Amps x Resistance)
Match the parts of a motor with the correct definition. Need to add coil (and forget about magnets) to the parts of the motor
Coil (the wire that acts as the electromagnet) Armature (the rotating shaft of the motor) brush (bars that connect the energy source to the moving parts of motor) commutator (split ring that breaks the flow of energy and reverses flow to power source)
Identify an example of wire that would have the most resistance in an electrical current. It would be _________ in diameter and ____________ in length.
A wire that is longer and thinner would have greater resistance
Know how microcircuits and household circuits are similar?
They both use switches and conductors
Know what you would call a device that uses a dial to control resistance in a circuit is called what?
A device to control resistance is called a rheostat or variable resistor
Know what kind of filament in a light bulb would produce the brightest light on a circuit with a small amount of current?
A filament with high resistance would produce the brightest light
Know the components of an electrochemical cell? There are two main parts.
Two electrodes of different metals and an electrolyte of liquid or paste
Know why would it be dangerous to use the improper amp fuse in a circuit? Ex. If I had a circuit that used a 20 Amp fuse and I replaced it with a 30 Amp fuse…what would be the problem?
If you use a fuse that has an improper amperage on it, it either won’t work properly if its too low or the circuit would be overloaded if too much amps were to be given off and it would malfunction
Know how many mV are in a volt.
There are 1000 mV in a volt
Be able to identify what a load is on a circuit.
A load is what the circuit is making work (light bulb, clock)
Know the main reason you would use a circuit breaker rather than fuses in a house?
Fuses have to be replaced, whereas a breaker just has to be switched on again.
Know what needs to be done to make a simple circuit work.
To make a simple circuit work the circuit has to be closed
Know what unit is used to measure the electrical energy of each electron in a circuit…or potential energy?
Voltage
