Electronics and Communication Engineering - Digital Electronics - Discussion
Discussion Forum : Digital Electronics - Section 3 (Q.No. 30)
30.
A dynamic RAM cell which holds 5 V has to be refreshed every 20 ms so that the stored voltage does not fall by more than 0.5 V. If the cell has a constant discharge current of 0.1 pA, the storage capacitance of cell is
Answer: Option
Explanation:
Q = 20 x 10-3 x 0.1 x 10-12 = 2 x 10-15 C and 
.
Discussion:
2 comments Page 1 of 1.
Manjusree said:
7 years ago
Please give the Explanation.
Animis said:
7 years ago
I = Q/t ; Q=It.
Q= (0.1pA)(20ms) = 2x10^-15 C.
C = Q/V.
C = 2x10^-15 / 0.5 V = 4x10^-15 F.
Q= (0.1pA)(20ms) = 2x10^-15 C.
C = Q/V.
C = 2x10^-15 / 0.5 V = 4x10^-15 F.
(1)
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