A periodic current wave starts at zero, rises instantaneously, then remains at a value of 20 A for 10 seconds, then decreases instantaneously, remaining at a value of -10 A for 20 seconds, and then repeats this cycle continuously. The RMS (root-mean-square) value of this wave is:

An alternating voltage source of variable angular frequency ω and fixed amplitude V is connected in series with a capacitance C and an electric bulb of resistance R (zero inductance). When ω is increased, what happens to the brightness of the bulb?

An inductor of reactance 1 Ω and a resistor of 2 Ω are connected in series to the terminals of a 6 V (rms) AC source. The power dissipated in the circuit is: