question_answer

The charge \[Q=\pi C\]is distributed on a thin semicircular ring of radius\[R=2m\]. There is a uniform electrostatic field \[\left| {\vec{E}} \right|=2N/C\]directed horizontal. The semicircular ring can rotate freely about a fixed vertical axis AB. Initially the ring is in static equilibrium a shown in figure. If we want to rotate it about the fixed axis by \[90{}^\circ \]then minimum work required on the ring is xJ. Find the value of x.

Answer:

8.00