Which of the following is a volt :
$Erg$ per $cm$
$Joule$ per $coulomb$
$Erg $ per $ampere$
$Newton / (coulomb \times m^2)$
A parallel plate capacitor has circular plates of $10\, cm$ radius separated by an air-gap of $1\, mm$ . It is charged by connecting the plates to a $100\, volt$ battery. Then the change in energy stored in the capacitor when the plates are moved to a distance of $1\, cm$ and the plates are maintained in connection with the battery, is
Which graph shows variation of electric field of a uniformly charged sphere $w.r.t.$ distance $(r)$ from the centre
An insulator plate is passed between the plates of a capacitor. The the displacement current
Four dipoles having charge $ \pm e$ are placed inside a sphere. The total flux of ${\vec E}$ coming out of the sphere is
Two point charges $+q$ and $-q$ are held fixed at $(-d, 0)$ and $(+d, 0)$ respectively of a $(x, y)$ coordinate system. Then