Topic 3 - Devices and systems convert energy with varying efficiencies

Question 1

What is Chemical Energy?

Answer 1

Potential energy stored in chemicals.

Question 2

What is Electrical Energy?

Answer 2

Energy transferred by movement of electrons.

Question 3

What is Mechanical Energy?

Answer 3

Motion or potential to move. (Energy of something moving)

Question 4

What is Thermal Energy?

Answer 4

Total kinetic energy of all particles.

Question 5

What is Energy?

Answer 5

Ability to do work.

Question 6

What is a Thermocouple?

Answer 6

Device which converts thermal energy to electrical energy.

Question 7

What is a Electromagnet?

Answer 7

Coil of insulated wire which becomes a magnet when currrent flows through it.

Question 8

What is Electric Fields?

Answer 8

Produced by electric charge.

Question 9

What is Magnetic Fields?

Answer 9

Produced by electric charges which are in motion.

Question 10

What are the 4 points of an Electrical Motor?

Answer 10

1. Magnet - Along the outside
2. Armature - Rotating shaft of the motor.
3. Commutator - Broken ring which breaks and reserves flow of current.
4. Brushes - Conducts electricity: Cell, battery, commutator

Question 11

What is a Transformer?

Answer 11

Device which converts or changes electricity at one voltage into electricity at a contrasting or different votlage.

Question 12

What is a Step-Up Transformer?

Answer 12

Increases voltage.

Question 13

What is a Step-Down Transformer?

Answer 13

Decreases or reduces the voltage.

Question 14

What is Electromagnetic Induction?

Answer 14

Creation of electric current in a conductor by changing or contrasting the magnetic field.

Question 15

What is a Direct Curent?

Answer 15

Current which flows in only 1 direction.

Question 16

What is a Alternating Current?

Answer 16

Current which flows back and forth 60 times per second.

Question 17

What is the Formula for Power?

Answer 17

P = V x I

Question 18

What is the Formula for Current?

Answer 18

I = P/V

Question 19

What is the Fomrula for Voltage?

Answer 19

V = P/I

Question 20

What is the Unit for Power?

Answer 20

Watts {W)

Question 21

What is the Unit for Energy?

Answer 21

Joules (J)

Question 22

What is the Unit for Time?

Answer 22

Seconds (S)

Question 23

What is the Formula for Electrical Energy?

Answer 23

E = P x T

Question 24

What is the Unit for Voltage?

Answer 24

Volts (V)

Question 25

How do you find the kilowatts?

Answer 25

You divide the watts by 1000.

Question 26

What are the 4 steps to solving the problem?

Answer 26

1. Identify the known qualities.
2. Indicate unknown quantity.
3. Use correct formula.
4. Solve the issue or problem.

Question 27

What does power mean?

Answer 27

The rate which a device converts energy.

Question 28

What is the Formula for Energy?

Answer 28

E = P x T

Question 29

What is the Law of Conservation of Energy?

Answer 29

Essential or Fundamental principle which energy cannot be created or destroyed.

Question 30

What is Efficiency?

Answer 30

Device (Ratio of useful energy which comes out of a device to the total energy which went in.

Question 31

What is the Formula for Efficiency?

Answer 31

Percent Efficiency =
Joules of useful output
———————————- x 100
Joules of input energy