Electrical Principles Unit Review

Question 1

What charges objects that attract each other have?

Answer 1

Opposite charges attract

Question 2

what form of energy, that energy in batteries is stored as?

Answer 2

Energy in batteries is stored as chemical energy

Question 3

What is the definition of current electricity?

Answer 3

Current electricity is the steady flow of charged particles (electrons)

Question 4

Give an example used to describe the behavior of current electricity.

Answer 4

Water flowing down a river would be used to model current electricity

Question 5

What unit we use to measure the energy used by an electrical device?

Answer 5

Energy used by an electrical device is measured in Joules

Question 6

How do you calculate total energy consumed?

Answer 6

E = P (Watts) x t (seconds)

Question 7

What main environmental problem is created by industrial production of carbon dioxide in large amounts?

Answer 7

Global Warming or climate change

Question 8

What is the energy transformation in a fuel cell?

Answer 8

Chemical to electrical

Question 9

How can we improve efficiency in fridges?

Answer 9

Add insulation and tighten the door seals. Make sure the motor is well oiled.

Question 10

How do you calculate output energy when given the efficiency of the machine and the input energy to make it work?

Answer 10

Output energy = % efficiency/100 x Joules input

Question 11

What does the efficiency rating of a machine tells you?

Answer 11

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.

Question 12

What are some examples of renewable and non-renewable resources?

Answer 12

Oil and gas non –renewable…water, trees are renewable

Question 13

What two things interact to make an electrical motor work?

Answer 13

Magnets and electromagnets interact to make a motor work

Question 14

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)

Answer 14

Batteries and energy in our bodies start as chemical energy

Question 15

Look at a picture of a circuit and identify what bulb(s) will light up when certain switches are closed or opened.

Answer 15

We did an example on the board

Question 16

Look at a picture of a circuit and identify if it is a series or parallel circuit.

Answer 16

Series circuit has all loads in one single loop and electricity can only flow in one path

Question 17

What example of a water tower and pipe would represent the biggest voltage and current?

Answer 17

A high water tower with a wider pipe would have the highest voltage and current

Question 18

What is the advantage of a parallel circuit over a series circuit?

Answer 18

A parallel circuit will still work if a load stops working

Question 19

How do identify examples of energy output and input. Answers will either be mechanical, chemical, thermal, and electrical.

Answer 19

Example: A heater has thermal output energy

Question 20

Know how to calculate voltage of an object when given amperage and resistance.

Answer 20

V = I x R (Amps x Resistance)

Question 21

Match the parts of a motor with the correct definition. Need to add coil (and forget about magnets) to the parts of the motor

Answer 21

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)

Question 22

Identify an example of wire that would have the most resistance in an electrical current. It would be _________ in diameter and ____________ in length.

Answer 22

A wire that is longer and thinner would have greater resistance

Question 23

Know how microcircuits and household circuits are similar?

Answer 23

They both use switches and conductors

Question 24

Know what you would call a device that uses a dial to control resistance in a circuit is called what?

Answer 24

A device to control resistance is called a rheostat or variable resistor

Question 25

Know what kind of filament in a light bulb would produce the brightest light on a circuit with a small amount of current?

Answer 25

A filament with high resistance would produce the brightest light

Question 26

Know the components of an electrochemical cell? There are two main parts.

Answer 26

Two electrodes of different metals and an electrolyte of liquid or paste

Question 27

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?

Answer 27

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

Question 28

Know how many mV are in a volt.

Answer 28

There are 1000 mV in a volt

Question 29

Be able to identify what a load is on a circuit.

Answer 29

A load is what the circuit is making work (light bulb, clock)

Question 30

Know the main reason you would use a circuit breaker rather than fuses in a house?

Answer 30

Fuses have to be replaced, whereas a breaker just has to be switched on again.

Question 31

Know what needs to be done to make a simple circuit work.

Answer 31

To make a simple circuit work the circuit has to be closed

Question 32

Know what unit is used to measure the electrical energy of each electron in a circuit…or potential energy?

Answer 32

Voltage