Application and selection of Zener diode

<img border="0" alt="" src="http://www.838dz.com/d/file/calculator/2010-02-15/ccebfe0707f4e5fbc72192e1cfba495b.jpg">

<img src="http://drr.ikcest.org/static/upload/67/67f3e31e-ef45-11e9-9273-00163e0618d6_m.jpg" />