IE unit 5

In the process of diode based rectification, the alternating input voltage is converted into

• an uncontrolle d alternating output
• an uncontr olled direct output
• a controlled alternating
• a controlled direct output voltage

In a half-wave rectifier with L Load, the

• current & voltage both are bi- directional
• current & voltage both are uni- directio
• current is always uni- directional but the voltage can be bi-directional
• current can be bi- directional or uni- directional but the voltage is always uni- directional

In UNCONTROLLED rectifiers with resitive , load current flow is

• Unidirectio nal
• Bidirecti onal
• Either (a) or (b)
• Negative

The given waveform represents the output of

• half wave rectifier with R load
• full wave rectifier with R load
• half wave rectifier with R L load
• full wave rectifier with RL load

Identify the given circuit

• half wave rectifier
• full wave rectifier with R
• half wave rectifier with R L
• full wave rectifier with RL load

In the below shown diode rectifier circuit,The diodes D1, D2 & D3 are connected to phases R,Y and B respectively as shown

• 0 to 90 degrees
• 30 to 150 degree s
• 0 to 180 degrees
• 30 to 180 degrees

The diodes D1, D2 & D3 are connected to phases R,Y and B receptively as shown

• 0 to 270 degrees
• 270 to 390 degrees
• 270 to 450
• 270 to 360 degrees

a three-phase half wave diode rectifier using 3 diodes,

• All diodes conduct together
• Only two diodes conduct at a time
• Only one diode conducts at a time
• Diodes will not conduct

In case of controlled rectifiers, the nature of the load current (continues or discontinuous) depends upon the

• type of load and firing
• only on the type of load
• only on the firing angle
• it is independent of all the parameters

Choose the requirements to turn-on the thyristors in a controlled full-wave rectifiers.

• The anode terminal of the thyristors is negative.
• The cathode terminal of the thyristor is positive
• The half-cycle of the AC supply voltage is positive.
• Applying a control signal to the gate terminal of the thyristors.