Electricity

Question 1

What are the factors affecting resistance?

Answer 1

• Type of material
• Cross sectional area: thickness
• Length: as it increases so does resistance
• Temperature: increase in temp=increase in resistance

Question 2

What is AC?

Answer 2

Alternating current- a flow of electrons that alternates in direction (wall outlet)

Question 3

What is direct current?

Answer 3

Direct current- a flow of electrons in one direction (batteries)

Question 4

What are the 9 ways of generating electricity?

Answer 4

Wind energy, solar energy, hydropower, natural gas, coal, petroleum, biomass, geothermal, uranium

Question 5

What are 2 advantages and 2 disadvantages about solar energy?

Answer 5

Advantages:

1. Non-polluting
2. Systems last 15-30 years

Disadvantages:

1. Expensive
2. Needs sunny weather

Question 6

What are 2 advantages and 2 disadvantages about wind energy?

Answer 6

Advantages:

1. No emissions
2. Affordable

Disadvantages:

1. Requires wind
2. Possible health risks

Question 7

What are 2 advantages and 2 disadvantages about Hydropower?

Answer 7

Advantages:

1. Reliable
2. No emissions

Disadvantages:

1. Environmental impacts (Dam)
2. Expensive

Question 8

What are 2 advantages and 2 disadvantages about Natural gas, Biomass, Coal and Petroleum energy?

Answer 8

Advantages:

1. Widely available
2. Abundant supplies

Disadvantages:

1. Emissions
2. Transportation is expensive

Question 9

What are 2 advantages and 2 disadvantages about Geothermal energy?

Answer 9

Advantages:

1. Efficient
2. Low cost

Disadvantages:
1. Expensive to start up

Question 10

What is an advantage and a disadvantage about uranium energy?

Answer 10

Advantage:
No emissions

Disadvantage:
Waste

Question 11

What is resistance? Where does it occur?

Answer 11

Resistance is anything that impedes, slows or resists the flow of electrons in a circuit. It occurs everywhere in the circuit but the most at the load

Question 12

What is the equation for Power?

Answer 12

P= V x I

P= power (w)
V= voltage (v)
I=current (a)

Question 13

What is the equation for current?

Answer 13

I= Q / T

I=current(a)
Q= coulombs of charge (c)
T= time (s)

Question 14

What is the equation for consumption?

Answer 14

E= P x T

E= energy consumption (kW•h)
P= power rating (w)
T= time (s)

Question 15

What is the equation for resistance?

Answer 15

R= V / I

R= resistance (ohms)
P= potential difference (v)
I= current (a)

Question 16

What is the equation for efficiency?

Answer 16

EE= EO / EI

EE= efficiency (%)
EO= energy output (j)
EI= energy input (j)

*output is never more than input, efficiency is never more than 100%

Question 17

What is the equation for voltage?

Answer 17

V= E / Q

V= potential difference (v)
E= energy (j)
Q= coulombs of charge (c)

Question 18

What is the equation for cost?

Answer 18

C= E x R

C= cost ($)
E= energy (j)
R= coulombs of charge (c)

Question 19

What is the ability to do work?

Answer 19

Energy [Joules [J]]

Question 20

What is the rate at which electric energy is produced or consumed over time?

Answer 20

Electric power

P– Watts or kilowatts

Question 21

What is: “how much electricity you use and are charged for”?

Answer 21

Electrical consumption

Question 22

What does electrical consumption depend on?

Answer 22

1. Duration of use

2. Number and efficiency of electrical devices using