विद्युत परिपथ आरेख (circuit diagram) में टेढ़ी-मेढ़ी रेखा और उसके बीच से तिरछे गुजरने वाले तीर का प्रतीक क्या दर्शाता है?

What is the primary function of a rheostat in an experimental electric circuit?

When checking a capacitor with an ohmmeter, the pointer initially deflects toward low resistance and then slowly returns toward an almost infinite resistance. If the pointer stops and stays at a relatively low resistance value (e.g., 50 kΩ), what does this indicate?