I'm puzzled by your question, I probably need more information, but as there are only 2 variables, frequency and time - you must be given one or the other unless it is a "bigger question" requiring wider info or other formulae. It sounds like you may need to find frequency first? I'll try a couple of possibilities: 1. Do you have a circuit you can take measurements from using instruments? If so, use an oscilloscope to display the waveform. On the screen use the graticule (the grid) together with the time per division on the X axis control - from this you can find the time taken to complete 1 cycle and then use f=1/T to find frequency. NOTE IF YOU ARE USING A HIGH VOLTAGE YOU MUST PROCEED WITH CAUTION SO AS TO AVOID A SERIOUS ELECTRIC SHOCK. Hopefully you have a lecturer/supervisor available to assist you! 2. If this is part of a larger calculation using another formula then you may need to do transposition - I'll briefly try to explain. Suppose you are using XL = 2pifL, assuming you're given (or can find) reactance and inductance then you can transpose to give f = XL/(2PIL). From f you can get the periodic time, T. I hope this is of some help to you. I have recently retired so don't tend to answer many questions. I wish you well in your studies, good luck 👍

you will need them if they ask you to draw the magnetic field.

@@la670 🤣

You're welcome. Please subscribe and recommend me to your friends and fellow students. I wish you well in your studies.

Thanks for watching the video. Unfortunately you appear to be mixing up two separate examples, example 2 on the left has nothing to do with example 2 on the right. Good luck with your studies.

Many thanks. I'm really glad you find them useful, I've had a lot of nice comments. I made virtually all the videos for my students during the lockdowns due to Covid 19. Unfortunately, some of the quality is not so good, so, if I get the time in the next couple of years I may re-record a few of them using a camera rather than a mobile phone - I couldn't get a decent camera at the time🙄😂 I've retired now so I doubt I'll have the time to produce anything new, we'll see how it goes! Please tell your friends to take a look. I wish you all the best in your studies, Zen

@@craigsclass-level3electric53 Great work man much appreciated 👍🏾

Hi, thanks for the comment. I'm not quite sure what you are referring to. These little video clips were made for my students during the lockdowns (as a result of Covid 19) and there may well be the odd error. My students would have a print out of the accompanying handout, which may answer some of your queries. In this clip I've referred to the induced emf measured in volts, V, and to velocity, v, measured in m/s. In the next few years I may edit or update or improve a few of the clips, but, I have now retired so do not plan to commit much time to them. I hope you find them useful - tell your friends about them! I wish you success in your studies, Zen

You're welcome!