Information, Electronics and Communications Technology (IECT)
The IECT domain examines how information is represented, processed, stored, transported and protected, plus the electronics and Indian policy framework around it. Expect applied items: a small calculation, a choice of protocol or medium, or a scenario naming the correct service or standard.
Inside the machine
Eight bits form a byte. Storage is usually quoted in decimal prefixes (1 MB = 10^6 bytes) while many operating systems display binary units (1 MiB = 2^20 bytes). In the stored-program model the CPU's ALU and control unit fetch instructions from memory; RAM is volatile working memory, ROM and firmware are not. The operating system manages processes, memory, files and devices; system software is distinguished from application software.
Electronics and signals
Analog signals vary continuously; digital signals take discrete levels. Logic gates (AND, OR, NOT, NAND, XOR) build combinational circuits. A transistor works as a switch or amplifier, a diode conducts in one direction, and an embedded system places a processor inside a dedicated device rather than a general-purpose computer.
Networks and communication
Bandwidth as capacity is measured in bits per second; frequency bandwidth is measured in hertz - different quantities that questions deliberately mix. Media are twisted pair, coaxial cable, optical fibre and radio. In TCP/IP the layers are link, internet, transport and application; TCP is connection-oriented and reliable, UDP is not. IPv4 private ranges are 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. DNS resolves names, DHCP assigns addresses, HTTPS is HTTP carried over TLS.
Indian context and law
Digital India, DigiLocker, UMANG, BharatNet and UPI (run by NPCI) are standard references. The IT Act 2000, amended in 2008, covers cyber offences; CERT-In handles incident response; the DPDP Act 2023 governs personal data.
Worked example
A 300 MB file is downloaded over an 8 Mbps link. Convert the rate: 8 Mbps ÷ 8 = 1 MB per second. Time = 300 ÷ 1 = 300 seconds, i.e. 5 minutes. The reasoning is the bit-to-byte conversion. Had the file been 300 MiB, the answer would be about 314.6 seconds (300 × 1.048576).
Traps that cost marks
Mixing bits and bytes, or MHz with Mbps; swapping TCP and UDP behaviour; calling a switch a router; assuming RAM retains data after power-off; confusing the IT Act 2000 with the DPDP Act 2023.