purely inductive load

[searley]

can any one show me how to go on with this ?

if a purley inductive load having an inductive reactance of 10 is connected across a 100v 50Hz supply,the power dissipated in the circuit will be ?

thanks.

 

[Andy™]

can any one show me how to go on with this ?if a purley inductive load having an inductive reactance of 10 is connected across a 100v 50Hz supply,the power dissipated in the circuit will be ?

thanks.

P=V

 

[searley]

andy.c can you explain where the V

 

[Andy™]

andy.c can you explain where the V

 

[SPECIAL LOCATION]

V

 

[Adrian41uk]

Guys,

I think we may have missed the point here..... the question says a PURELY inductive load. In which case it has no resistive component only an inductive one, hence the POWER disipated is zero Watts.

I agree that it will consume reactive power, in VAr, and hence have an apparent power, in VA, but it cant consume any WATTS.

Adrian

 

[a1]

Hello Adrian,

Welcome to the forum.

 

[danny7299]

Guys,I think we may have missed the point here..... The question says a PURELY inductive load. In which case it has no resistive component only an inductive one, hence the POWER dissipated is zero Watts.

Adrian

I thought this as well but the fact the he says "inductive reactance of 10" suggested that it has resistance (XL=2*Pi*F*L). ...,

Shouldn

 

[Andy™]

I thought this as well but the fact the he says "inductive reactance of 10" suggested that it has resistance (XL=2*Pi*F*L). ...,Shouldn

 

[SPECIAL LOCATION]

Guys,I think we may have missed the point here..... the question says a PURELY inductive load. In which case it has no resistive component only an inductive one, hence the POWER disipated is zero Watts.

I agree that it will consume reactive power, in VAr, and hence have an apparent power, in VA, but it cant consume any WATTS.

Adrian

Hello Adrian...... you may well be right....

and indeed we may well all need to put our pants on our heads:O

But then saying that it has also been known for bods not to write the question exactly correctly as well?

after all Searley does say...

a "PURLEY" not Purely??? :^O :^O:^O

purley kings and purley queens!!!!!! how many sequins on their coats?

Anyway welcome to the forum good to have you here...

we shall have to wait and see is Searley can input a bit more?

for the benefit of any others reading who may be confused how something can consume zero power...

this little link may shed a bit of light...

Guiness Drink

 

[searley]

hi

the way i put the question on is the way it is on the city & guilds paper.

on to me level 3 now do city & guilds make the questions more clearer as the corses go on ?

 

[Andy™]

on to me level 3 now do city & guilds make the questions more clearer as the corses go on ?

Is the earth flat?

 

[searley]

i`ll take that as a NO then andy.c.

 

[Andy™]

i`ll take that as a NO then andy.c.

that would be correct....

 

[Adrian41uk]

If we assume, for the moment, that the question is poorly worded and assume that we have been given the impedance of the inductor and not the inductance. However, we still have a problem...... if we calaculate the current flowing through this inductor and muliply by the applied voltage we will get the apparent power which is measured in VA (not WATTS)

The problem here is that not all the apparent power is dissipated..... only real power can be dissipated. The Reactive power component merely flows backwards and forwards between the source and the load each half cycle.

We don't have enough information available to split the apparent power into its component parts of real & reactive powers.

Just my twopenny worth.......

 

[mikey-c]

The question has been worded pity much as City and Guilds ask them. I'm sure they mean to confuse people.

The answer they are looking for is 0 watts. I'm not too sure why, is it because it's purely inductive so has a power factor of 0? Hence 0 x anything = 0.

I've learnt to spot the question by the 'purely' in it.

 

[SPECIAL LOCATION]

The question has been worded pity much as City and Guilds ask them. I'm sure they mean to confuse people.The answer they are looking for is 0 watts. I'm not too sure why, is it because it's purely inductive so has a power factor of 0? Hence 0 x anything = 0.I've learnt to spot the question by the 'purely' in it.

Oh they do enjoy tripping people up! :|

 

[SPECIAL LOCATION]

If we assume, for the moment, that the question is poorly worded and assume that we have been given the impedance of the inductor and not the inductance. However, we still have a problem...... if we calaculate the current flowing through this inductor and muliply by the applied voltage we will get the apparent power which is measured in VA (not WATTS)The problem here is that not all the apparent power is dissipated..... only real power can be dissipated. The Reactive power component merely flows backwards and forwards between the source and the load each half cycle.

We don't have enough information available to split the apparent power into its component parts of real & reactive powers.

Just my twopenny worth.......

I have got to say I think your twopenny worth is actually more like a sixpence!

and your two post are quite correct! ; )Applaud Smiley

 

[searley]

just found out what city & guilds have missed off it is reactance of 10 ohms they missed the ohms out after the 10.

so is the answer in the above can`t find me calc to work this out ?

love city & guilds.