Q-Which of the below mentioned statements is false regarding a p-n junction diode?
a) Diode are uncontrolled devices
b) Diodes are rectifying devices
c) Diodes are unidirectional devices
d) Diodes have three terminals
………………
Answer: d
Explanation: Diode is a two terminal device, anode & cathode are the two terminals.
Q-Lets assume that the doping density in the p-region is 10-9 cm-3 & in the n-region is 10-17cm-3, as such the p-n junction so formed would be termed as a
a) p– n–
b) p+ n–
c) p– n+
d) p+ n+
……………..
Answer: b
Explanation: Doping density is greater in the p-region compared to the n-region.
Q-Which of the following is true in case of a forward biased p-n junction diode?
a) The positive terminal of the battery sucks electrons from the p-region
b) The positive terminal of the battery injects electrons into the p-region
c) The negative terminal of the battery sucks electrons from the p-region
d) None of the above mentioned statements are true
……………
Answer: a
Explanation: The diode is forward biased, positive is connected to p & vice-versa, as such batter provides EMF to drive electrons from n-region to p-region.
Q-To make a signal diode suitable for high current & high voltage carrying applications with minimum losses, ________
a) a lightly doped n layer is grown between the two p & n layers
b) a heavily doped n layer is grown between the two p & n layers
c) a lightly doped p layer is grown between the two p & n layers
d) a heavily doped p layer is grown between the two p & n layers
…………………
Answer: a
Explanation: The above process simply the one used to manufacture power diodes.
Q-Which of the following is true in case of a power diode with R load?
a) I grows almost linearly with V
b) I decays almost linearly with V
c) I is independent of V
d) I initial grows than decays
…………
Answer: a
Explanation: R load therefore V and I are linear and in phase.
Q- Ideally the voltage drop across a conducting diode must be
a) ∞
b) 0
c) higher than the forward biased voltage
d) equal to the forward biased voltage
………………
Answer: b
Explanation: Ideal conduction = No losses.
Q-In a Schottky diode, the aluminum metal acts as a __________
a) anode
b) cathode
c) gate
d) common terminal
………….
Answer: a
Explanation: The Al (Metal) always acts as the anode.
Q-As compared to a p-n junction device of equal rating, the Schottky diode has
a) lower reverse voltage rating
b) lower reverse leakage current
c) higher Switching time
d) higher cut-in voltage
…………..
Answer: a
Explanation: Low reverse voltage rating is the only drawback against a p-n junction diode.
Q-Zener diodes allow a current to flow in the reverse direction, when the
a) voltage reaches above a certain value
b) temperature reaches above a certain value
c) current always flows in the reverse direction only
d) current cannot flow in the reverse direction
……………..
Answer: a
Explanation: Zener diode has voltage regulating property. When voltage reaches above a certain value (Zener voltage), current starts to flow in the reverse direction.
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