When the current changes from $$ + 2A$$ to $$-2A$$ in $$0.05$$ second, an $$e.m.f.$$ of $$8$$ $$V$$ is inducted in a coil. The coefficient of self- induction of the coil is

The core of any transformer is laminated so as to

To demonstrate the phenomenon of interference, we require two sources which emit radiation

To get three images of a single object, one should have two plane mirrors at an angle of