A two winding transformer is feeding a single phase half wave rectifier circuit. The load is purely resistive. The rms value of transformer secondary current is Is and rms value of load current in Irms. Then

• A. Is = Irms irrespective of the value of firing angle
• B. Is = 0.5 Irms irrespective of the value of firing angle
• C. Is = Irms if firing angle is less than 30°
• D. Is = Irms if firing angle is more than 30°