Q.1.
For a certain SCR configuration, the below shown waveform is obtained. Find the value of the average output voltage with α =& Vs =V.
- a) 50.27 V
- b) 100.8 V
- c) 140 V
- d) 120 V
Q.2.
A single-phase half wave circuit has Vs =V with a R load ofΩ. Find the average load current at α = 30°.
- a) 1.45 A
- b) 0.57 A
- c) 0.96 A
- d) 2.3 A
Q.3.
A single phaseV, 1 kW heater is connected across a 1-phaseV,Hz supply through an SCR. The firing angle of the SCR is adjusted to give a rms voltage ofV. Find the power absorbed by the heater element.
- a) 250 watts
- b) 1 kW
- c) 454 watts
- d) 378 watts
Q.4.
For a single phase half-wave thyristor circuit with R load, the power delivered to the resistive load is
- a) (average load voltage) x (average load current)
- b) (rms supply voltage)2/R
- c) (rms load voltage)2/R
- d) (average load voltage)/R
Q.5.
For a single phase half-wave thyristor circuit with R load, the input power factor is given by
- a) rms source voltage/total rms line current
- b) rms input power/power delivered to the load
- c) cos α
- d) power delivered to load/input VA
Q.6.
For the below shown circuit,
- a) gradually rising
- b) going from positive to negative
- c) gradually decaying
- d) zero
Q.7.
For the below shown circuit,
- a) load voltage & load current are both zero
- b) only load voltage is zero
- c) only load current is zero
- d) both are non zero & non negative
Q.8.
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
- a) γ = β+α
- b) γ = β-α
- c) γ = β/α
- d) γ = α/β
Q.9.
For a half-wave single phase thyristor rectifier circuit with any type of load the _______ + _________ waves must ideally give the supply voltage waveform.
- a) load voltage, load current
- b) load voltage, thyristor voltage
- c) supply current, load voltage
- d) supply current, thyristor voltage
Q.10.
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
- a) β to α
- b) β to 2π+α
- c) β to 2π
- d) β to 2β