169. The most widely used rectifier is
A. half-wave rectifier
B. centre-tap full-wave rectifier
C. bridge full-wave rectifier
D. none of the above

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170. Zener diodes are used primarily as
A. amplifiers
B. voltage regulators
C. rectifiers
D. oscillators

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171. A pn junction that radiates energy as light instead of as heat is called a
A. LED
B. photo-diode
C. photocell
D. Zener diode

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172. The capacitance of a varactor diode increases when reverse voltage across it
A. decreases
B. increases
C. breaks down
D. stores charge

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173. To display the digit 8 in a seven-segment indicator
A. C must be lighted
B. G must be off
C. F must be on
D. All segments must be lighted

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174. A photo-diode is normally
A. forward-biased
B. reverse-biased
C. Neither forward nor reverse biased
D. Emitting light

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175. When the reverse voltage increases, the junction capacitance
A. decreases
B. stays the same
C. increases
D. has more bandwidth

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