78. In positive logic, logic state 1 corresponds to
A. positive yoltage
B. higher voltage level
C. zero voltage level
D. lower voltage level

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79. In negative logic, the logic state 1 corresponds to
A. negative voltage
B. zero voltage
C. more negative voltage
D. lower voltage level

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80. The voltage levels of a negative logic system
A. must necessarily be negative
B. may be negative or positive
C. must necessarily be positive
D. must necessarily be OV and ?5V

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81. The output of a 2-input OR gate is zero only when its
A. both inputs are 0
B. either input is 1
C. both inputs are 1
D. either input is 0

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82.  An XOR gate produces an output only when its two inputs are
A. high
B. low
C. different
D. same

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83. An AND gate
A. implements logic addition
B. is equivalent to a series switching circuit
C. is an any-or-all gate
D. is equivalent to a parallel switching circuit

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84. When an input electrical signal A = 10100 is applied to a NOT gate, its output signal is
A.1011
B.10101
C.10100
D.101

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