8. LED's do not require
A. heating
B. warm up time
C. both (a) and (b) above
D. none of the above

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9. A zener diode
A. has a high forward voltage rating
B. has a sharp breakdown at low reverse voltage
C. can be used as an amplifier
D. none of the above

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10. The conduction in a SCR is controlled by
A. gate
B. anode
C. cathode
D. all of the above

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11. When a SCR is conducting it has
A. infinitely large resistance
B. resistance of few megaohms
C. low resistance
D. zero resistance

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12. The characteristics of a thyristor closely resemble to the characteristics of
A. PN-j unction
B. Constant voltage source
C. Constant current source
D. 'Thyratron gas tube

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13. Which of the following is not a four layer diode?
A. SCR
B. Triac
C. Thyrisor
D. Diac

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14. A triac is like a
A. unidirectional SCR
B. bidirectional SCR
C. NPN transistor
D. PNP transistor

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