Ans: (4) 0.32
In 1 msec, refresh=32 times
memory cycle= 1msec/250nsec= 4000 times
Therefore % refresh time:
(32*100nsec)/(4000*250nsec)
= 3200/1000000=0.0032
= 0.32%
One can also refer:
The percentage of memory's total operating time required for refresh is 0.32 %
Explanation :
Memory cycle time = 250nsec = 250 x 10⁻⁹ s
Number of refreshes in 1 msec = 32
=>Number of refreshes in 1 s = 32000
=> Number of refreshes in 250 x 10⁻⁹ s = 32000 x 250 x 10⁻⁹
= 8 x 10⁻³
Time taken by 1 refresh cycle = 100 nsec = 100 x 10⁻⁹ = 10⁻⁷ s
=> Time taken by 8 x 10⁻³ refresh cycles = 8 x 10⁻³ x 10⁻⁷
= 8 x 10⁻¹⁰ sec
Hence percentage of time for refresh = 8x10⁻¹⁰/250x10⁻⁹ x100%
= 0.32 %
Refer:
https://brainly.in/question/7072365#readmore