The voltage of an $ac$ supply varies with time $(t)$  as $V = 120\sin 100\,\pi \,t\cos 100\pi \,t.$ The maximum voltage and frequency respectively are

The output sinusoidal current versus time curve of a rectifier is shown in the figure. The average value of output current in this case is

The r.m.s. voltage of domestic electricity supply is $220$ $volt$ . Electrical appliances should be designed to withstand an instantaneous voltage of......$V$

An alternating voltage $v\left( t \right) = 220\,\sin \,100\pi l\,volt$ is applied to a purely resistive load of $50\,\Omega $ . The time taken for the current to rise from half of the peak value of the peak value is.....$ms$

Three alternating voltage sources $V_1$ = $3 sin \omega t $ volt , $V_2= 5  sin(\omega t + \phi _1)$ volt and $V_3 = 5  sin(\omega t -\phi_2 )$ volt connected across a resistance $R= \sqrt {\frac{7}{3}} \Omega $ as shown in the figure (where $ \phi_1$  and $ \phi_2$   corresponds to $30^o $ and $127^o $ respectively). Find the peak current (in Amp) through the resistor

The mean value of current for half cycle for a current variation shown by the graph is