Help With This Question?

[MattyH]

I have got my 203 exam tomorrow so I am reading through my notes, but I have forgot how to do this question:

The inductive reactance of a 100 mH coil when connected to a 50 Hz supply will be:

A) 5 Ohms
B) 20 Ohms
C) 31.42 Ohms
D) 31.42 Kilo Ohms

Also any tips on the 203 exam?

 

[trev]

Come on Matty you know the rule, you have to have a go at the answer yourself first

 

[MattyH]

2 x pye x 50 x 100?

 

[MarkieSparkie]

2 x pye x 50 x 100?

100mH not 100H try again mate.

 

[mickys86]

I have got my 203 exam tomorrow so I am reading through my notes, but I have forgot how to do this question:

The inductive reactance of a 100 mH coil when connected to a 50 Hz supply will be:

A) 5 Ohms
B) 20 Ohms
C) 31.42 Ohms
D) 31.42 Kilo Ohms

Also any tips on the 203 exam?

Good luck on your exam, I have just passed my 301 and I wish you all the best.

The biggest tip I can give you is to read the question slowly to ensure you aren't missing something. (like the thing you missed in this question)

in one of the questions in my mock exam I had an answer of 3183 ohms. None of the multiple choice answers was near that but after 20 minutes Of looking at it I realised that one of the answers said 3.18 K ohms which is obviously correct.

Have you looked on the Swindon massive revision site?

 

[ebow72]

I have got my 203 exam tomorrow so I am reading through my notes, but I have forgot how to do this question:

The inductive reactance of a 100 mH coil when connected to a 50 Hz supply will be:

A) 5 Ohms
B) 20 Ohms
C) 31.42 Ohms
D) 31.42 Kilo Ohms

Also any tips on the 203 exam?

Before you can answer the question do you know the formula for Inductive Reactance? This is the first starting point mate...once you've got that, you have the answer..
If you don't know it I can remind you of it, if you like??

 

[ebow72]

2π f l

don't know if you can read that or not?? but have a go from that

 

[MattyH]

Thanks for the replies guys! Yeah. I just realised I had to change the mega henrys into normal henrys (divide by 1000 and got 0.1) and i got 31.41. but the closest answer was 31.42 which i presume is right! Also I am using swindon massive.

 

[MattyH]

Also does L stand for reactance and what does NF stand for?

 

[ebow72]

If it's a small case n it's nano and F I assume is farads. If this is for capacitance then you're rocking mate..

 

[Guest123]

Inductive reactance (XL) = 2TT f l

f = frequency in Hz
l= inductance in henrys

 

[Richard Burns]

Thanks for the replies guys! Yeah. I just realised I had to change the mega henrys into normal henrys (divide by 1000 and got 0.1) and i got 31.41. but the closest answer was 31.42 which i presume is right! Also I am using swindon massive.

Note that the value you had was milli (m) Henrys not mega (M) Henrys, but your calculation is correct.

Also does L stand for reactance and what does NF stand for?

Lenny has given the answer as well as Ebow but the NF to which I think you are referring is the greek letter Pi (3.14159...) multiplied by frequency f. It does look like Nf.