If 100 J of electrical energy goes into a light bulb how much energy comes out of the light bulb?

Answer 1

The same 100 J will come out of the light bulb (not all of it as visible light).

Answer 2

Joule is the unit of energy. Watt is the unit of power. One Joule provides one Watt for one second. A 100 Watt lamp uses 100 Joules per second.

Answer

Power is the rate of doing work. Work is measured in joules, so power is measured in joules per second. However, in SI, a joule per second is given a special name: the watt. So a 100-W lamp consumes 100 J of energy per second.

Answer 3

The question is asking how much energy is consumed by a 100 watt bulb because, in some countries a "unit of electricity" is equivalent to a kilowatt.hour (kW.h). The term, 'unit', is derived from the name, 'Board of Trade Unit'; the Board of Trade was at one time the British Government body that regulated energy prices.

The watt is an unit of power, which is the rate of doing work or, in this case, the rate at which energy is obtained from the supplier. Power isn't 'consumed'; it is simply a rate, the rate at which energy is consumed. For the purpose of billing its customers, energy is measured in kilowatt hours (power multiplied by time, is a measure of energy consumed)

A 100 watt bulb consumes 0.1 kilowatt hour. That is 1/10 (one tenth) of a kilowatt-hour and, therefore, one 1/10 of a 'unit' of energy.

How much it actually costs you always depends on the exact price you pay for each kilowatt.hour of energy.

So, if the electricity supply company you use charges, say, 30 cents per unit of electricity (kW.h) then running that 100 watt bulb for one hour would cost you 3 cents.

Answer 4

A light bulb is not only rated in watts, it is rated in voltage also. The lamp has to be operated on the voltage specified by the manufacturer of the light bulb. Too high a voltage and the lamp life will be shortened. Too low a voltage and you will not obtain the full wattage of the lamp.

Answer 5

It's 100 watts times 3600 seconds, that's 360,000 joules of energy. A joule is 1 watt for 1 second.

Answer 6

None.

An incandescent bulb use electrical energy(in this case 100 W of it) and turns it into light energy.

Answer 7

What is meant by the term "total energy"? A 100 watt light bulb consumes 100 watts.