What is the approximate percentage value of the ratio of maximum voltage to its rms value in an $LCR$ $AC$ circuit (in $\%$)?

$A$ resistance of $20 \Omega$ is connected to an alternating current source of $110 V$. If the frequency of the $A.C.$ source is $50 Hz$,then the time taken by the current to change from its maximum value to the $R.M.S.$ value is

Find the time required for a $50 \text{ Hz}$ alternating current to reach its $rms$ value from zero. (in $\text{ ms}$)

If the emf of an $AC$ source is given by $E = 6 \sin \omega t + 4 \sin 2 \omega t \text{ V}$,then the rms value of the emf is

$A$ 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 its $rms$ value.

The heat produced in a resistor by an $AC$ current is three times the heat produced by a $2 \, A$ $DC$ current. What is the $rms$ value of the $AC$ current in $A$?