Rupali Bank PLC
Post: Assistant Network Engineer
Exam Date: 15-01-2022, Exam Taker: CTI
(i) What is the capacity of disk pack?
(ii) If the format overhead is 32 bytes per sector, what is the formatted disk space?
(iii)If the disk is rotating at 3600 RPM, what is the data transfer rate?
What is the capacity of the disk pack?
Answer:
Capacity of disk pack = Total number of surfaces × Number of tracks per surface × Number of sectors per track × Number of bytes per sector
= 16 × 128 × 256 × 512 bytes = 256 MB
If the format overhead is 32 bytes per sector, what is the formatted disk space?
Answer:
Total number of sectors = Total number of surfaces × Number of tracks per surface × Number of sectors per track
= 16 × 128 × 256 sectors = 219 sectors
Number of bits required to address the sector = 19 bits
Formatting overhead = Total number of sectors × Overhead per sector
= 219 × 32 bytes = 219 × 25 bytes = 224 bytes = 16 MB
Formatted disk space = Total disk space – Formatting overhead
= 256 MB – 16 MB = 240 MB
If the disk is rotating at 3600 RPM, what is the data transfer rate?
Answer:
Number of rotations in one second = (3600 / 60) rotations/sec = 60 rotations/sec
Data transfer rate = Number of heads × Capacity of one track × Number of rotations in one second
= 16 × (256 × 512 bytes) × 60
= 24 × 28 × 29 × 60 bytes/sec
= 60 × 221 bytes/sec = 120 Mbps
2. Job arrival time and execution time of Operating system tasks table is given, find out
| Job | Arrival Time | Execution Time |
|---|---|---|
| A | 0 | 10 |
| B | 3 | 7 |
| C | 5 | 3 |
Average waiting time



Transmission rate = (1.5 Mbps) / 16 = (1.5 x 106) / 16 Kbps
Now, the time to send data is:
Time = file size / transmission rate + delay
Substituting the values:
Time = (2 × 500,000 × 16) / (1.5 × 106) + 300 / 1000 = 10.7 sec
In order: 20, 30,35, 40,45, 50, 55, 65, 75
Preorder: 50, 40, 30, 20, 35, 45, 65, 55, 70
50
/ \
40 65
/ \ / \
30 45 55 75
/ \
20 35
Procedure sumNodes(Node* root)
int sumNodes(Node* root)
{
if (root == NULL)
return 0;
return root->data + sumNodes(root->left) + sumNodes(root->right);
}Sample Input: 192.168.0.0
Sample Output: Class C
#include <iostream>
#include <string>
#include <sstream>
using namespace std;
// Function to determine the class of an IPv4 address
string getIPAddressClass(const string& ipAddress) {
stringstream ss(ipAddress);
string token;
// Get the first octet
getline(ss, token, '.');
// Convert first octet to integer
int firstOctet = stoi(token);
// Determine class
if (firstOctet >= 1 && firstOctet <= 127) {
return "Class A";
}
else if (firstOctet >= 128 && firstOctet <= 191) {
return "Class B";
}
else if (firstOctet >= 192 && firstOctet <= 223) {
return "Class C";
}
else if (firstOctet >= 224 && firstOctet <= 239) {
return "Class D";
}
else if (firstOctet >= 240 && firstOctet <= 255) {
return "Class E";
}
else {
return "Invalid IP address";
}
}
int main() {
string ipAddress;
cin >> ipAddress;
string ipAddressClass = getIPAddressClass(ipAddress);
cout << "IP Address: " << ipAddress
<< " belongs to " << ipAddressClass << endl;
return 0;
}

First, calculate the number of required bits for each subnet:
- For 4000 hosts: Needs at least 12 bits for host portion (212 = 4096).
- For 2000 hosts: Needs at least 11 bits for host portion (211 = 2048).
- For 6000 hosts: Needs at least 13 bits for host portion (213 = 8192).
- For 8000 hosts: Needs at least 13 bits for host portion (213 = 8192).
Subnet Calculations:
Department C (6000 hosts)
Subnet Mask: 172.16.0.0/19 (because 32 – 13 = 19 bits for network portion).
Subnet Range: 172.16.0.0 – 172.16.31.255
First IP: 172.16.0.1
Last IP: 172.16.31.254
Department D (8000 hosts)
Subnet Mask: 172.16.32.0/19 (same as above).
Subnet Range: 172.16.32.0 – 172.16.63.255
First IP: 172.16.32.1
Last IP: 172.16.63.254
Department A (4000 hosts)
Subnet Mask: 172.16.64.0/20 (because 32 – 12 = 20 bits for network portion).
Subnet Range: 172.16.64.0 – 172.16.79.255
First IP: 172.16.64.1
Last IP: 172.16.79.254
Department B (2000 hosts)
Subnet Mask: 172.16.80.0/21 (because 32 – 11 = 21 bits for network portion).
Subnet Range: 172.16.80.0 – 172.16.95.255
First IP: 172.16.80.1
Last IP: 172.16.95.254
(i) Find out the logical expression in Sum of product for 2bit binary input.

i) For 2 bit binary, we can find 00, 01, 10, 11 and the equivalent decimal value is
0,1,2,3.
Now, For Binary= 00 (Decimal= 0)= abcdef is high
For Binary= 01 (Decimal=1)= bc is high
For Binary= 10 (Decimal=2) = abged is high
For Binary=11 (Decimal=3)= abgcd is high


(i) Draw ER diagram
(ii) Convert the ER diagram to relations(Table)

ER Diagram → Relational Tables Conversion
Below is the relational schema (tables) derived from the ER diagram.
1. Coach Table
Coach(Coach_ID, Coach_name)
* Primary Key: Coach_ID
2. Team Table
Team(Team_ID, Team_name, Coach_ID)
* Primary Key: Team_ID
* Foreign Key: Coach_ID → Coach(Coach_ID)
3. Player Table
Player(Player_ID, Player_name, Player_position, Team_ID)
* Primary Key: Player_ID
* Foreign Key: Team_ID → Team(Team_ID)
4. Stadium Table
Stadium(Stadium_ID, Stadium_name, Stadium_location)
* Primary Key: Stadium_ID
5. Game Table
Game(Game_no, Game_name, Game_time)
* Primary Key: Game_no
6. Match Table
Match(Match_ID, Match_date, Match_result, Stadium_ID, Game_no)
* Primary Key: Match_ID
* Foreign Key:
* Stadium_ID → Stadium(Stadium_ID)
* Game_no → Game(Game_no)
(a) Increased High Costs
(b) Draining Battery of devices
(c) Increased infrastructure development cost
(a) Increased High Costs:
The development of 5G infrastructure is very expensive. It requires upgrading existing networks and installing new equipment. The cost includes both the initial setup and continuous maintenance to ensure reliable and high-speed connectivity. Because of these high costs, service providers may charge higher prices for 5G services.
(b) Draining Battery of Devices:
5G connectivity consumes more power than previous mobile network generations. As a result, mobile devices connected to 5G networks may experience faster battery drain. Users may need to charge their devices more frequently, and some devices may also become hotter while using 5G.
(c) Increased Infrastructure Development Cost:
Building the infrastructure for 5G requires installing new technologies such as small cell towers and advanced networking equipment. Many older devices are not compatible with 5G networks, so they must be replaced with newer devices. This significantly increases the overall cost of implementing 5G networks.
5G Technology-এর অসুবিধা
(a) Increased High Costs:
5G network তৈরি করতে অনেক বেশি খরচ হয়। বিদ্যমান network infrastructure আপগ্রেড করতে হয় এবং নতুন equipment স্থাপন করতে হয়। এর মধ্যে initial development cost এবং ongoing maintenance cost দুটিই অন্তর্ভুক্ত থাকে। ফলে 5G service ব্যবহারকারীদের জন্য তুলনামূলকভাবে বেশি ব্যয়বহুল হতে পারে।
(b) Draining Battery of Devices:
5G connectivity আগের mobile network generation-এর তুলনায় বেশি power ব্যবহার করে। এজন্য 5G ব্যবহার করলে mobile device-এর battery দ্রুত শেষ হয়ে যায়। ব্যবহারকারীদের device বেশি বার charge করতে হতে পারে এবং অনেক সময় 5G ব্যবহার করার সময় phone গরম হয়ে যায়।
(c) Increased Infrastructure Development Cost:
5G support করার জন্য নতুন infrastructure তৈরি করতে হয়। এর জন্য small cell tower, নতুন networking equipment এবং অন্যান্য technology স্থাপন করতে হয়। অনেক পুরনো device 5G compatible নয়, তাই সেগুলোকে নতুন device দিয়ে replace করতে হয়। এসব কারণে 5G network implementation-এর মোট খরচ অনেক বেড়ে যায়।
8. Below tables are given, Employee (employee_id, name, salary, department) Leave
(employee_id, date, reason, no_leaves) Holiday (Date, description)

SELECT employee_id, COUNT(employee_id)
FROM Leave
GROUP BY employee_id;
SELECT *
FROM employee
WHERE employee_id IN (
SELECT employee_id
FROM leave
GROUP BY employee_id
HAVING COUNT(employee_id) > 5
);
