Questions
1
Which of the following isn’t a type of rectifier?
Answer: None of the mentioned
2
For a half-wave rectifier having diode voltage VD and supply input of VI, the diode conducts for π – 2Θ, where Θ is given by
Answer: sin-1 VD/VI
3
The diode rectifier works well enough if the supply voltage is much than greater than 0.7V. For smaller voltage (of few hundreds of millivolt) input which of the following can be used?
Answer: Superdiode
4
A simple diode rectifier has ‘ripples’ in the output wave which makes it unsuitable as a DC source. To overcome this one can use
Answer: A capacitor in parallel to the load resistance
6
The internal efficiency of a mercury arc rectifier depends on
Answer: Voltage only
7
The voltage drop at anode, in a mercury arc rectifier is due to
Answer: Energy spent in overcoming the electrostatic field
8
Mercury, in arc rectifiers, is chosen for cathode because
Answer: All of the above
9
The cathode voltage drop in a mercury arc rectifier is due to
Answer: Expenditure of energy in liberating electrons from the mercury
10
If cathode and anode connections in a mercury arc rectifier are interchanged
Answer: The rectifier will not operate
11
In a three-phase mercury arc rectifier anode conducts for
Answer: One third of a cycle
12
Which of the following is the loss within the mercury arc rectifier chamber?
Answer: All of the above
13
A commuting rectifier consists of commutator driven by
Answer: A synchronous motor
16
Which of the following mercury arc rectifier will deliver least undulating current?
Answer: Six phase
17
In a mercury arc rectifier characteristic blue luminosity is due to
Answer: Ionization
18
In a mercury arc rectifier.............flow from anode to cathode
Answer: Ions
19
A mercury arc rectifier possesses ...............regulation characteristics
Answer: Straight line
20
The potential drop in the arc in a mercury arc rectifier varies
Answer: None of the above
