answersLogoWhite

0


Best Answer

80

Use the following formula:

W - Q = [m c (T1 - T2)]water + [m c (T1 - T2)]kettle

Where W = work done in joules

Q = heat transfer away from the kettle

m = mass of water (and mass of kettle)

c = specific heat capacity of water (and of the material from which kettle is made)

T1 = initial temperature of water/kettle

T2 = final temperature of water/kettle

User Avatar

Wiki User

12y ago
This answer is:
User Avatar
More answers
User Avatar

Wiki User

10y ago

It depends on how many liters of water. An average kettle holds up to 1.7 liters and takes 3KW. If it takes 3 minutes( 1/20 of an hour) to boil that's 3/20 of a KWh, = 0.15 KWh.

Doing the thermal energy sum, you have say 1.5 liter = 1.5 kg of water raising from say 10 C to 100 C, that's 90 C raise and 1500 grams of water so that makes 135,000 calories. 1 calorie = 4.2 Joules, so we have 567,000 Joules.

1 watt = 1 Joule/sec , 1 KW = 1000 Joules/sec, so 1 KWh = 1000 x 3600 Joules (3600 secs in 1 hour), 1 KWh = 3,600,000 Joules. So 567,000 Joules = 0.1575 KWh.

So the two sums give similar results. If you do a more exact comparison, you could find the efficiency of the kettle from the difference in the two figures, there is bound to be some loss of electrical power, but it should not be much.

Alternative Answers.

For a more accurate answer, use the following formula -

W - Q = [m c (T1 - T2)]water + [m c (T1 - T2)]kettle

Where

W = work done in joules

Q = heat transfer away from the kettle

m = mass of water (and mass of kettle)

c = specific heat capacity of water (and of the material from which kettle is made)

T1 = initial temperature of water/kettle

T2 = final temperature of water/kettle

Then convert your answer from joules to kilowatt hours.

However, the REALLY simple way is to time how long it takes for your kettle to boil, then multiply its nameplate power rating (in kilowatts) by that time (expressed in hours)!

This answer is:
User Avatar

User Avatar

Wiki User

15y ago

If you want some boiling water to make tea or coffee, you have to use energy to produce it. Why should you consider it wasted? After all, it is not a new fad to want hot water, in the old days people would keep a kettle on the fire, but we don't usually have fires these days, we use electricity or natural gas.

What is a waste is to fill the kettle if you only want enough water for one or two drinks. Just put in enough for what you intend to use and that is not a waste.

You can work out the energy used by looking up the rating of the kettle in watts, and timing how long it takes to boil, and working it out in KWh.

This answer is:
User Avatar

User Avatar

Wiki User

9y ago

The average kettle is rated about 1500 Watts. Watts = amps x volts. amps = watts/volts. 1500/120 = 12.5 amps.

Answer for UK

Modern kettles are typically rated just short of 3 kW, because they operate at 230 V and can draw up to 13 A from a socket outlet (receptacle).

This answer is:
User Avatar

User Avatar

Wiki User

11y ago

Watts is the wrong unit. It is a measure of energy usage, not total power consumed. This question is like saying "How many Km per Hour do you go in an hour".

A "Joule" is the scientific unit of energy.

1 Watt = 1 Joule per second.

A typical kettle uses between 1 and 2 Kw (Kilowatts).

So in one hour it would use 1.5 x 1 x 60 x 60 = 5400 Joules.

Electricity bills are usually quoted in "Kilowatt Hours" (KwHr) instead of Joules

So in one hour a kettle uses 1.5 x 1 = 1.5 Kilowatt Hour

This answer is:
User Avatar

User Avatar

Wiki User

12y ago

A kilowatt is 1000 watts. It depends on the manufactures wattage rating of the kettle. Most kettles fall within the 1250 watt range. In North America, the electrical code limits a 15 amp circuit to 80% of its rated load capacity. This limits the circuit rating to 15 x 120 = 1800 watts x 80% = 1440 watts. Manufactures stay below this limit otherwise there would be a conflict with the electrical code and a circuit could become overloaded when the kettle is plugged in. So to find the kilowatts of a kettle take the watts that are printed on the label and divide it by 1000 to get its kW value.

This answer is:
User Avatar

User Avatar

Wiki User

7y ago

In North America an electric kettle is usually rated at 1500 watts. Any wattage above this value would trip the circuit breaker because of an over current. The equation used is A = W/V. 1500 /120 = 12.5 amps. At this wattage it stays within the limits of the electrical code's 80% rule of loading of a #14 conductor. Most homes are wired with a #14 size conductor rated at 15 amps, for their branch circuitry.

An example, a kettle at 2000 watts will draw 2000/120 = 16.6 amps, at 2500 watts the draw will be 2500/120 = 20.8 amps and 3000 watts it will draw 3000/120 = 25 amps.


To change from watts to kilowatts divide the figure by 1000. This will give you the value in kilowatts. It is this kilowatt value that is read by the utility meter on your home.


So to answer the question a kettle will use 1.5 kilowatts of power all the time that it is on. If it was left on for an hour without it being turned off you would be charged for 1.5 kilowatt hours of power use.

This answer is:
User Avatar

User Avatar

Wiki User

7y ago

Kettles are usually rated as 3KWh. Meaning - if it is left on for an hour - it will use three units of electricity.

This answer is:
User Avatar

User Avatar

Music Club.k

Lvl 2
3y ago

This Help to loose Weight Find On email tiwarinikhil068@

This answer is:
User Avatar

User Avatar

Wiki User

9y ago

it uses about 300 WATS of energy

This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: How many amps does an average kettle use?
Write your answer...
Submit
Still have questions?
magnify glass
imp