Structure of bipolar transistor
<a href="//commons.wikimedia.org/wiki/User:Shaddack" title="User:Shaddack">User:Shaddack</a>, <a href="//commons.wikimedia.org/wiki/User:Predatorix" title="User:Predatorix">User:Predatorix</a>
<div class="thumb tright"><div class="thumbinner" style="width:222px;"><a href="//commons.wikimedia.org/wiki/File:Bipolar_transistor.png" class="image"><img src="https://upload.wikimedia.org/wikipedia/commons/thumb/4/4b/Bipolar_transistor.png/220px-Bipolar_transistor.png" decoding="async" width="220" height="165" class="thumbimage" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/4/4b/Bipolar_transistor.png/330px-Bipolar_transistor.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/4/4b/Bipolar_transistor.png/440px-Bipolar_transistor.png 2x" data-file-width="800" data-file-height="600"></a>  <div class="thumbcaption"><div class="magnify"><a href="//commons.wikimedia.org/wiki/File:Bipolar_transistor.png" class="internal" title="Enlarge"></a></div>Bipolar transistor</div></div></div>