A resistance of $40 \,\Omega$ is connected to a source of alternating current rated $220\, V , 50 Hz$. Find the time taken by the current to change from its maximum value to $ms$ value
$2.5\, ms$
$1.25\, ms$
$2.5 \,s$
$0.25 \,s$
In $ac$ circuit when $ac$ ammeter is connected it reads $i$ current if a student uses $dc$ ammeter in place of $ac$ ammeter the reading in the $dc$ ammeter will be:
Give definition and formula of root mean square plot graph of current versus $\omega t$.
Both alternating current and direct current are measured in amperes. But how is the ampere defined for an alternating current ?
In alternating current circuits, the $a.c$. meters measure
Hot wire ammeters are used for measuring