#Madeeasy_test_series 2019

Question

Answer 1

Though this may seem too lengthy but actually it is not. I have written in detail for which it has taken up too much space but once you write few of the states it won't take much time to complete the table.

So,

X =0 from T=0 to before T=10 and X=1 from T=10 to before T=90, X=0 from T=90 to -----

NOT gate has 5ns delay and AND delay has 10ns delay. So change at Y will occur after every 5ns and change at Z will occur after every 10ns. Initially at T=0 Y=1 (given). Now lets see :

Time T	X	Y	Z=XY	Next operation
0 (Initial condition)	0	1	0	At T+10 i.e. T=10, Z= XY=0*1=0, Y will not change(it will change after Z changes)
10	1	1	0	At T+5 i.e. T=15, Y= Z'=1, Z will change at T+10=20. Z=1*1=1
15	1	1	0	At T+5 i.e. T=20, Y will be Z'=1, Z will change at T+10=25. Z=1*1=1
20	1	1	1	At T+5 i.e. T=25, Y will be Z'=0, Z will change at T+10=30. Z=1*1=1
25	1	0	1	At T+5 i.e. T=30, Y will be Z'=0, Z will change at T+10=35. Z=1*0=0
30	1	0	1	At T+5 i.e. T=35, Y will be Z'=0, Z will change at T+10=40. Z=1*0=0
35	1	0	0	At T+5 i.e. T=40, Y will be Z'=1, Z will change at T+10=45. Z=1*0=0
40	1	1	0	At T+5 i.e. T=45, Y will be Z'=1, Z will change at T+10=50. Z=1*1=1
45	1	1	0	At T+5 i.e. T=50, Y will be Z'=1, Z will change at T+10=55. Z=1*1=1
50	1	1	1	At T+5 i.e. T=55, Y will be Z'=0, Z will change at T+10=60. Z=1*1=1
55	1	0	1	At T+5 i.e. T=60, Y will be Z'=0, Z will change at T+10=65. Z=1*0=0
60	1	0	1	At T+5 i.e. T=65, Y will be Z'=0, Z will change at T+10=70. Z=1*0=0
65	1	0	0	At T+5 i.e. T=70, Y will be Z'=1, Z will change at T+10=75. Z=1*0=0
70	1	1	0	At T+5 i.e. T=75, Y will be Z'=1, Z will change at T+10=80. Z=1*1=1
75	1	1	0	At T+5 i.e. T=80, Y will be Z'=1, Z will change at T+10=85. Z=1*1=1
80	1	1	1	At T+5 i.e. T=85, Y will be Z'=0, Z will change at T+10=90. Z=1*1=1
85	1	0	1	At T+5 i.e. T=90, Y will be Z'=0, Z will change at T+10=95. Z=1*0=0
90	0	0	1	At T+5 i.e. T=95, Y will be Z'=0, Z will change at T+10=100. Z=0*0=0
95	0	0	0	At T+5 i.e. T=100, Y will be Z'=1, Z will change at T+10=105. Z=0*0=0
100	0	1	0	END

Taking the values of Z we draw a timing diagram which will look like

Comments

time                                        output(z)

0-10                                         0

10-20                                        0

20-30                                       1

30-40                                        0

40-50                                         1

50-60                                        0

60-70                                         1

70-80                                         0

80-90                                           1

90-100                                        0

total changes =8 where is my mistake????