I could do with some help... thanks !

[robinson]

hey everyone due to such a high number of detailed responces when i ask a question on here, (rather than my tutors responce of... "look in your notes." i was wondering if you would be able to help me with a few questions.

I know this is kind of a simple question but i am getting lost somewhere with my working out because i dont get any of the answers that are given...

A single phase circuit dissipates 1.5kw of power and operates at a power factor of 0.8 when connected to a 230v supply. The current flowing in the circuit will be...

5.2A

6.5A

8.15A

10.4A

Many thanks keep looking at this thread i will most probably need more of your help thanks you again

Ps All your help last month made me get a credit in my exam!!!

 

[a1]

Your tutor is correct, with respect mate - you are supposed to look through your notes.

However, show us your working out and we can have a look to see where you are going wrong (if you are going wrong at all, that is, it has been known for mock questions' answers to be wrong too).

Admin.

 

[Theorysparky]

1.5kw x 1000/230 x 0.8 = 8.15amps

good site

Useful Formulas

thanks for letting us know that we gave you a helping hand for your exam !!!!!!!

 

[ianmacd]

You need some brackets there otherwise its not correct.

Following BODMAS you get 5.217...

Following sequentially you get 5.217....

(1.5 x 1000) / (230 x 0.8) = 8.152.... the correct answer.

Just as punctuation in english, brackets are vital in maths.

 

[robinson]

thank you very much! appriciate it, thank you for the site on formulas! and thanks admin but i didnt have very good notes on this subject for some reason, and tbh this site is so much better than anything that is in our notes!

 

[robinson]

another one??

An Ac circuit has an inductive reactance of 13 ohms, a capacitive reactance of 23 ohms and a resistance of 18 ohms. calculate the impedance...

thank you

 

[a1]

Don't quote me on this, but here is my go at working it out?

A

 

[robinson]

Thank you for your reply admin, but i do have the answers and its 4.97 ohms ? dont know if that shines some more light?

 

[Theorysparky]

You need some brackets there otherwise its not correct.Following BODMAS you get 5.217...

Following sequentially you get 5.217....

(1.5 x 1000) / (230 x 0.8) = 8.152.... the correct answer.

Just as punctuation in english, brackets are vital in maths.

Ian

Thorough as always mate

i made the assumption that the op would have worked that out............i was rushing to get out !!!!

 

[Ali]

An Ac circuit has an inductive reactance of 13 ohms, a capacitive reactance of 23 ohms and a resistance of 18 ohms. calculate the impedance...

Oh dear,

I get 20.6ohms

 

[robinson]

haha i think this maybe one of the mistake ones in the paper...

 

[philbas]

Oh dear,I get 20.6ohms

So do I

 

[Ali]

Now I know I'm not the only one to get 20.6ohms, I'll explain how I got it...

The total reactance is the capacitive reactance-inductive reactance.

X=23-13=10ohms

In an AC circuit, Z

 

[philbas]

Now I know I'm not the only one to get 20.6ohms, I'll explain how I got it...The total reactance is the capacitive reactance-inductive reactance.

X=23-13=10ohms

In an AC circuit, Z

 

[Andy™]

Now I know I'm not the only one to get 20.6ohms, I'll explain how I got it...The total reactance is the capacitive reactance-inductive reactance.

X=23-13=10ohms

In an AC circuit, Z

 

[robinson]

thanks everyone maybe its just a wrong question i wondered why i kept getting the answer wrong on it!!

 

[a1]

I will go an sit in the corner with this Dunce's hat on. :_|