Discuss Exin CDCP Exam Topic 4 Question 25

By what are magnetic fields of the type 'H' or 'B' created?

AMagnetic fields are created when an electric current flows; the greater the current, the stronger the magnetic field.

BMagnetic fields are created by the magnetic flux of the earth which varies per month.

CMagnetic fields are created by voltage; the greater the voltage, the stronger the magnetic field.

DMagnetic fields are created when there is a high level of common mode noise (CMN); the greater the common mode noise (CMN), the stronger the magnetic field.

Suggested Answer: A

According to the CDCP Preparation Guide1, magnetic fields of the type 'H' or 'B' are created when an electric current flows through a conductor, such as a wire or a coil. The magnetic field strength 'H' is proportional to the current 'I' and the number of turns 'N' of the coil, and inversely proportional to the length 'l' of the coil. The magnetic flux density 'B' is proportional to the magnetic field strength 'H' and the permeability '' of the medium in which the magnetic field exists. The greater the current, the stronger the magnetic field and the magnetic flux density. The relationship between 'H', 'B', 'I', 'N', 'l', and '' can be expressed by the following equations:

H = N I / l

B = H

1: CDCP Preparation Guide, page 23, section 2.4.2.1 2: Difference between B and H in magnetic fields?3, page 1, section 1 4: Magnetic field | Definition & Facts5, page 1, section 1

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26 comments · newest first

Xuan 11 months ago

I heard the Earth's magnetic flux changes, but not sure if that creates fields like this.

Tiera 11 months ago

Totally agree, current is key for magnetic fields!

Vernice 11 months ago

Wait, are you saying common mode noise can create magnetic fields? Sounds sketchy.

Mitzie 12 months ago

Magnetic fields are definitely created by electric current!

Kris 12 months ago

I remember a practice question about how magnetic fields are generated, and it definitely involved electric current. I think option A is the most accurate here.

Desmond 12 months ago

I recall studying that magnetic fields can be influenced by various factors, but I don't think common mode noise is a primary cause. That one seems off to me.

Gilberto 1 year ago

I'm not so sure about the options, but I feel like magnetic fields are more related to electric currents than to voltage. I might be mixing it up with another concept.

Herman 1 year ago

I think magnetic fields are mainly created by electric currents, right? I remember something about how the strength of the field increases with the current.

Margot 1 year ago

I remember learning that magnetic fields are created by moving electric charges, so A is definitely the right answer here.

Bong 1 year ago

Option A seems like the most straightforward answer, but I want to double-check the other choices just to be sure.

Jimmie 1 year ago

The question mentions "H" and "B" fields, so I think the key is understanding the relationship between electric and magnetic fields. I'll review that concept before selecting an answer.

Felice 1 year ago

I'm pretty sure magnetic fields are created by electric current, so I'll go with option A.

Cordelia 1 year ago

Hmm, I'm a bit confused about this one. I'll have to think it through carefully before answering.

My 2 years ago

I agree with Jesusita, the relationship between electric current and magnetic fields is well-established in science.

Art 2 years ago

Haha, voltage creating magnetic fields? That's a good one! Obviously, it's the current that does the trick. Option A is the way to go.

Jesusita 2 years ago

I think option A makes sense because I remember learning about electromagnetism in physics class.

Graciela 2 years ago

I was stuck between A and D, but I think A makes the most sense. Common mode noise doesn't create magnetic fields, it's all about that electric current flow.

Olive 2 years ago

↳ replying to Graciela

Common mode noise doesn't create magnetic fields, so A is the correct answer.

Ryan 2 years ago

↳ replying to Graciela

Yeah, the greater the current, the stronger the magnetic field.

Shanice 2 years ago

↳ replying to Graciela

I agree, magnetic fields are definitely created by electric current flow.

Luann 2 years ago

Option A is clearly the correct answer. Magnetic fields are created by the flow of electric current, just like we learned in physics class.

Alida 2 years ago

↳ replying to Luann

So, it's the current that determines the strength of the magnetic field. Interesting.

Delpha 2 years ago

↳ replying to Luann

I remember learning that in physics class. It's all coming back to me now.

Roosevelt 2 years ago

↳ replying to Luann

Yes, that's correct. The flow of electric current is what creates magnetic fields.

Olene 2 years ago

↳ replying to Luann

I think the answer is A) Magnetic fields are created when an electric current flows; the greater the current, the stronger the magnetic field.

France 2 years ago

A) Magnetic fields are created when an electric current flows; the greater the current, the stronger the magnetic field.

Exin CDCP Exam - Topic 4 Question 25 Discussion