Computer aptitude guide for SBI Clerk Mains

Where Computer Aptitude sits in the exam

Computer Aptitude is not a separate paper. It is part of the Mains section Reasoning Ability & Computer Aptitude, which has 50 questions, 60 marks and 45 minutes. SBI's booklet says this section also judges your "aptitude/knowledge for working with computer". The split between reasoning and computer questions is not published and can vary by shift.

Because computer questions take 10 to 20 seconds each when you know the fact, answering them first frees time for puzzles. The flip side is that a wrong answer here is pure loss: these are recall questions, so if you do not know a fact and cannot rule out options, leave it. Accuracy in this part should be close to 100% after three weeks of preparation.

Fundamentals and generations

• CPU has the ALU (arithmetic and logic), the control unit and registers.
• Generations: first, vacuum tubes; second, transistors; third, integrated circuits; fourth, microprocessors (VLSI); fifth, artificial intelligence and parallel processing.
• Types: supercomputer, mainframe, minicomputer, microcomputer (personal computers).
• Number systems: binary (base 2), octal (base 8), decimal (base 10), hexadecimal (base 16). Decimal 10 is 1010 in binary and A in hexadecimal.

Memory and storage

Order by speed, fastest first: registers, cache, RAM, secondary storage.

Software and operating systems

• System software runs the computer (operating system, device drivers, utilities). Application software does user tasks (word processors, browsers).
• The operating system manages memory, processes, files and devices. Examples: Windows, Linux, macOS, Android.
• A compiler translates a whole program at once; an interpreter translates line by line; an assembler converts assembly language to machine code.
• Booting is starting the computer; a cold boot starts from power off, a warm boot is a restart.

MS Office and shortcut keys

In Excel, remember that a cell address is column letter plus row number (B7), $ makes a reference absolute ($B$7), and every formula starts with "=".

Networking and internet

• Network types by area: PAN, LAN, MAN, WAN. The internet is the largest WAN.
• Devices: a router connects different networks; a switch connects devices within a LAN; a modem converts digital and analogue signals.
• OSI model has 7 layers: physical, data link, network, transport, session, presentation, application.
• Protocols: HTTP and HTTPS for web pages, FTP for file transfer, SMTP for sending email, POP3 and IMAP for receiving it, DNS for converting domain names into IP addresses.
• Addresses: IPv4 is 32-bit, IPv6 is 128-bit, a MAC address is 48-bit.
• Email fields: CC sends a visible copy; BCC sends a copy without showing that recipient to others.

Security, databases and new technology

Security

• Virus attaches to files; worm spreads on its own across networks; Trojan hides inside useful-looking software; ransomware locks data and demands payment.
• Phishing tricks people into revealing passwords or card details through fake messages or websites. A firewall filters network traffic.

DBMS

• A table has rows (records or tuples) and columns (fields or attributes). A primary key uniquely identifies a row; a foreign key links to another table's primary key.
• SQL is used to query relational databases: SELECT, INSERT, UPDATE, DELETE.

New technology

Know one-line meanings of artificial intelligence, machine learning, cloud computing (IaaS, PaaS, SaaS), the Internet of Things, blockchain and big data.

How to prepare in 3 weeks

Keep a one-page sheet of full forms (CPU, ALU, BIOS, URL, HTTP, LAN, ISP) and revise it every few days.

Full forms worth memorising

Banking-linked terms such as MICR, ATM and core banking are worth an extra look, because the exam is for a bank.

Questions about this