Explanation:
Since the current flowing through an ideal capacitor is described by equation:

for voltage across the capacitor constant with time the current is:

Open switch has this characteristics (Constant voltage and zero current).
Answer:
In an a.c generator, slip rings are used.
Adaptation: <em>They</em><em> </em><em>are</em><em> </em><em>not</em><em> </em><em>directly</em><em> </em><em>connected</em><em> </em><em>directly</em><em> </em><em>to</em><em> </em><em>carbon</em><em> </em><em>brushes</em><em>,</em><em> </em><em>hence</em><em> </em><em>donot</em><em> </em><em>come</em><em> </em><em>into</em><em> </em><em>contact</em><em> </em><em>when</em><em> </em><em>the</em><em> </em><em>rectangular</em><em> </em><em>coil</em><em> </em><em>rotates</em><em>.</em>
Explanation:

Never gonna give you up
Never gonna let you down
Never gonna run around and desert you
Never gonna make you cry
Never gonna say goodbye
Never gonna tell a lie and hurt you