DC Circuit Analysis: Voltage Divider (Part 2)

[blissx3]

excellent, thanks!

[brahmdeep121]

thank you

[lukamontuana]

And how did you calulate Rx to 40k?

[infinitybit666]

Go to original equation Req = (Rx * 10k) / (Rx + 10k); substitute 8k for Rx and you have 8k = (Rx * 10k) / (Rx + 10k); multiply both sides by (Rx + 10k); this reduces to 8k * (Rx + 10k) = Rx * 10k, which equals 8kRx + 80k = 10kRx; balance the equation and you have 80k = 2kRx; divide both sides by 2 and you get Rx = 40k

[infinitybit666]

edit: substitute 8k for Req rather than Rx

[spiderman1321]

how did you calculate the R equivalent to equal 8k??? i struggle with maths.

[drjcircuits]

In video, start with 8=10*Req/(2k+Req). Divide by 10 on both sides of this equation. This yields, 0.8=Req/(2k+Req). Multiply both sides of equation by 2k+Req. This yields, 1.6k+.8*Req=Req. Subtract .8*Req from both sides. This yields, 1.6K=.2k*Req. Divide by .2k on both sides of equation to yield Req=8k. Hope this helps. Dr J

[dosili]

thanks..

very clear... :)