Test: Single Phase HW AC-DC - 1 - Electrical Engineering (EE) MCQ

 In the method of phase control, the phase relationship between ___ & ___ is controlled by varying the firing angle

In a single phase half-wave thyristor circuit with R load & Vs=Vm sinωt, the maximum value of the load current can be given by

Below shown ideal circuit is triggered at a firing angle of α. The voltage across the SCR is zero from ωt =

Below shown ideal circuit is triggered at a firing angle of α. From ωt = π to 2π+α

For a single phase thyristor circuit with R load & firing angle α, the conduction angle can be given by

For the below given circuit with firing angle α & angular frequency of ω, the circuit turn-off time in secs can be given by

 A single-phase half-wave thyristor circuit with R load is triggered at an angle of α = 0°. As such, the maximum value of the average output voltage would be given byConsider Vs = Vm sinωt.

For a certain SCR configuration, the below shown waveform is obtained. Find the value of the average output voltage with α = 30° & Vs = 240 V.

A single-phase half wave circuit has Vs = 230 V with a R load of 100 Ω. Find the average load current at α = 30°.

 A single phase 230 V, 1 kW heater is connected across a 1-phase 230 V, 50 Hz supply through an SCR. The firing angle of the SCR is adjusted to give a rms voltage of 155 V. Find the power absorbed by the heater element.

 For a single phase half-wave thyristor circuit with R load, the power delivered to the resistive load is

For a single phase half-wave thyristor circuit with R load, the input power factor is given by

 For the below shown circuit,

The load voltage waveform from ωt = π to ωt = π+α = β (extinction angle) is

For the below shown circuit,

The SCR is gated at α. At ωt = π

In case of a single-phase half-wave circuit with RL load, with firing angle α and extinction angle β, the conduction angle γ can be written as

For a half-wave single phase thyristor rectifier circuit with any type of load the _______ + _________ waves must ideally give the supply voltage waveform.

In case of a single-phase half-wave circuit with RL load, with firing angle α and extinction angle β, the thyristor is reversed biased from