Need help with homework

[sidk47]

Hi guys,

I have tried the circuit as attached to this post.I got the answer as 11.945mHenry.

However the answer given in the book is 4mH. I totally don't know how they got that.

Also I am unable to solve complicated circuits that they mention as to be done in Electronics Workbench. That's a bummer because I can't seem to solve the more complicated questions by hand.

Also is learning through textbooks the best way to go about learning electronics(I am in chapter 13 of Robbin's circuit analysis) or is there a better way?


Thanks in advance, any help would be most sincerely appreciated.

 

[Harald Kapp]

4 mH is correct.
Show us your steps to arrive at 11.945 mH.
Be sure you know:

• What is the total inductance of two inductors in parallel?
• What is the inductance of two inductors in series?

is learning through textbooks the best way to go about learning electronics

The answer totally depends on several factors like:

• What do you already know?
• Do you generally learn easily from written text or do you prefer an instructor?

The thing is that you can (mostly) ask an instructor if you have trouble understanding an issue, you can't ask a textbook (at least it won't answer ). In my opinion you get the most value from either way of teaching/learning if you complement the instructions by building and testing circuits. For starters, follow the simple circuits from the instructions. Once you get more proficient, create your own little circuits.

Looking forward to your answers to the 1st issue,
Harald

 

[duke37]

I prefer a common ground line across the bottom of the diagram rather than lumps of ground floating in the air, it is easier to see what is happening.

There is a 6mH inductance connected to ground so the answer must be less than this with more inductance connected across it.

Calculate the inductance of 28.5mH and 19mH in parallel, then add 0.6mH in series.

Calculate this value in parallel with 6mH.

By using all values in mH, then the answer will be in mH.

I learned about electronics by mending devices, building kits, designing simple circuits and running transmitters. My theoretical knowledge is therefore not great but is sufficient for what I do. I have lashed out and bought a copy of "The art of electronics" for expanding my knowledge.

 

[sidk47]

Hi guys I got the right answer. I'd like to thank you all for your help. The reason I got the wrong answer was that I was doing 6 parallel 0.6 in series with 19 parallel 28.5. But when I did 6 ||(0.6+19||28.5) I got the right answer. Thank you all for your help. I just know the first 13 chapters of the book Robbin's circuit analysis. One thing on my life's bucketlist is to finish that book in totality. I generally learn things easier from textbooks than from instructors.

 

[hevans1944]

I generally learn things easier from textbooks than from instructors.

You will learn even more if you follow Harald's advice in post #2: use what you learn from textbooks to build and test your own circuits. Start simple with just a few passive components and a multi-meter and a wall-wart for DC power. You can add a small "filament transformer" providing 6.3 V AC for experiments with AC and build or buy an audio oscillator for frequency agility.

For now, I would stick with resistors and capacitors because most multi-meters don't measure inductance, but quite a few measure resistance and capacitance (as well as AC and DC voltage and current) and this is the type of multi-meter you should get. There are inexpensive LCR (inductor, capacitor, resistor) meters available on the Internet, but while learning, a good digital multi-meter is all you need. Buy the best you can afford if you plan to make a career of electronics, but even an inexpensive one is better than no meter at all.