SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
SNC 1P: Electricity
always the smaller number
always the larger number
Calculating Efficiency
Efficiency: Efficiency is the measure of how much useful energy an electrical device produces compared to the energy supplied to the device.
Symbol Unit
Energy in Joules (J)
Energy out Joules (J)
Efficiency Eff %
Sample Problem
A light bulb uses 85J of energy and produces 35J of light energy? Calculate the percent of efficiency of the light bulb.
Solution
G iven
R equired
A nalysis
S olution
Paraphrase
=
SNC 1P: Electricity
1. Calculate the percent efficiency of an electric motor that uses 15 000 J of energy
to produce 11 500 J of useful energy.
G iven
R equired
A nalysis
S olution
Paraphrase
2. Calculate the percent efficiency of an incandescent light bulb that produces 2500
J of light energy from 50 000 J of electrical energy.
G iven
R equired
A nalysis
S olution
Paraphrase
3. Calculate the percent efficiency of a kettle that uses 240 000 J of energy to boil
600 mL of water, which requires 196 000 J of energy.
G iven
R equired
A nalysis
S olution
