Question

Suppose we can download 10 pages per minut
E. A page has 24 lines on average and a line has 80 characters on averag
E. Assuming 8 bits per character, the bit rate is :

• A. $6.4 \times 10^5$ bps
• B. $1.536 \times 10^5$ bps
• C. $8.64 \times 10^3$ bps
• D. $2.56 \times 10^3$ bps

Hint:

Always convert all units (minutes to seconds, characters to bits) before doing the final division to avoid simple calculation errors.

Answer 1

The Correct Option is D

Concept:
• Bit rate is defined as the number of bits transmitted or received per unit of time (typically per second, denoted as bps).
• To calculate the bit rate, we must determine the total data volume in bits and divide it by the total time in seconds.

Step 1: Calculate the number of bits in one page
Each line has \(80\) characters, and each character is \(8\) bits:
\(\text{Bits per line} = 80 \times 8 = 640 \text{ bits}\)
Each page has \(24\) lines:
\(\text{Bits per page} = 24 \times 640 = 15360 \text{ bits}\)

Step 2: Calculate the total bits downloaded per minute
We download \(10\) pages in one minute:
\(\text{Total bits per minute} = 10 \times 15360 = 153600 \text{ bits/minute}\)

Step 3: Convert the rate to bits per second (bps)
Since there are \(60\) seconds in a minute:
\(\text{Bit rate} = \frac{153600 \text{ bits}}{60 \text{ seconds}} = 2560 \text{ bps}\)

Step 4: Express in scientific notation to match options
\(2560 = 2.56 \times 10^3 \text{ bps}\).