1)50v 1 khz 2)50v 100hz 3)50v dc
3. Because 1 and 2 are AC which introduce inductive reactance into circuit, ( impedance, or AC resistance) which will reduce the voltage across the lamp and current in the circuit. Inductive reactance XL 2pi x L x F. Where L is inductance and F frequency. So the greater the frequency, the greater the reactance XL. AC resistance (Impedance Z) sq.rt (R sq + xL sq + xC sq). xC Capacitive reactance.
3) because the impedance of the inductor is zero at DC.
