127.  The invalid state of a NAND latch occurs when
A. S = 1, C = 0
B. S = 0, C = 1
C. S = 1, C=I
D. S = 0, C = 0

---

128.  The invalid state of a NOR latch occurs when
A. S =1, C =0
B. S =0, C = 1
C. S =1, C =1
D. S =0, C = 0

---

129.  Like a latch, the flip-flop belongs to a category of logic circuit knownes
A. monostable multivibrators
B. astable multivibrators
C. bistable multivibrators
D. none of these

---

130.  Which of the following flip-flops is used as a latch?
A. J-K flip-flop
B. S-C flip-flop
C. D flip-flop
D. T flip-flop

---

131.  A flip-flop which can have an uncertain output state is :
A._ J-K flip-flop
B. S-C flip-flop
C. D flip-flop
D. T flip-flop

---

132.  The purpose of a clock input to a flip-flop is to
A. clear the device
B. set the device
C. always cause the output tochange the states
D. cause the output to assume a state dependent on the controlling (S - C, J-K or D) inputs

---

133. A feature that distinguished the J-K flip-flop from an S-C flip-flop is the
A. toggle condition
B. preset input
C. type of clock
D. clear input

---