Step-by-step explanation:
The RMS value of the sinusoidal wave = 20V.
It's peak value or the amplitude = Vmax= 20×√2 Volts.
Peak voltage at 180° or π radians = 0 volt.
peak voltage at 270 degrees = -20√2 volt.
peak voltage of the sinusoidal wave = 10V.
RMS voltage = 10/√2 = 5√2 volts.
RMS current through 10 ohm resistor= 5√2/10 = 1/√2 Amp.
I_peak = 10v/10ohm = 1amp.