What is the byte capacity of a drum which is 5 inch high, 10 inch diameter, and which has 60 tracks per inch and bit density of 800 bits per inch?

A. 942000 bytes

B. 9712478 bytes

C. 192300 bytes

D. 14384 bytes

E. None of the above

Answer: Option A

Solution(By Examveda Team)

The byte capacity of a drum which is 5 inch high, 10 inch diameter, and which has 60 tracks per inch and bit density of 800 bits per inch,
Total capacity = (areal density) x (total surface area)
Areal density = 60 x 800 = 48000 bits per inch
Total surface area = 2πrh = 2 × π × 5 × 5 = 50π
Total capacity = $$\frac{{\left( {50 \times 3.14 \times 48000} \right)}}{8}$$     = 942000 bytes.