The alternating current in a circuit is described by the graph shown in Fig 7.4. Show rms current in this graph.

Can the instantaneous power output of an ac source ever be negative? Can the average power output be negative?

In series LCR circuit, the plot of I_max vs ω is shown in Fig 7.3. Find the bandwidth and mark in the figure.

How does the sign of the phase angle ϕ, by which the supply voltage leads the current in an LCR series circuit, change as the supply frequency is gradually increased from very low to very high values.

A device ‘X’ is connected to an a .c source. The variation of voltage, current and power in one complete cycle is shown in Fig 7.5.

(a) Which curve shows power consumption over a full cycle?

(b) What is the average power consumption over a cycle?

(c) Identify the device ‘X’.