Bangladesh Bank; Assistant Maintenance Engineer Written Test: 2016প্রশ্ন ও সমাধান

Both are specialised input devices used for automated document reading, but they capture different kinds of marks.

Aspect	OMR (Optical Mark Reader)	MICR (Magnetic Ink Character Recognition)
What it reads	Pencil/pen marks (filled bubbles)	Characters printed in special magnetic ink
Technology	Reflects light off the paper to detect marks	Magnetises and reads special ink characters
Typical use	OMR answer sheets, surveys, lottery slips	Bank cheques — account/branch/cheque numbers
Error rate	Sensitive to stray/incomplete marks	Very low — fast and highly reliable
Common sector	Examination boards	Banking industry

graph LR
    subgraph OMR
    S1[Pencil-marked sheet] --> R1[Optical sensor] --> D1[Digitised responses]
    end
    subgraph MICR
    S2[Cheque with magnetic-ink numbers] --> R2[Magnetic read head] --> D2[Account/cheque data]
    end

Exam takeaway: OMR reads optical marks (used in exams/surveys); MICR reads magnetised ink characters (used almost exclusively by banks for cheque processing) — the mnemonic is "O for Optical bubbles, M for Magnetic money."

• URL (Uniform Resource Locator): the human-readable address of a resource on a network, specifying the protocol, host, and path — e.g. https://www.example.com/page.html. It is one specific kind of URI (Uniform Resource Identifier) and is used for web pages (http/https), file transfer (ftp), and email links (mailto).

• VoIP (Voice over Internet Protocol): a technology that digitises voice signals and carries them as data packets over an IP network (including the Internet) instead of the traditional analogue phone network — e.g. WhatsApp calls, Zoom, Skype. It reduces call cost by reusing existing data infrastructure.

• Broadband: a high-capacity, always-on data transmission technology that carries multiple signals/channels simultaneously over a single medium (fibre, coaxial cable, DSL, or radio), giving much higher speed than legacy dial-up. It is the physical/data-link layer foundation that makes services like VoIP practical.

graph LR
    User -->|"types URL"| Browser --> DNS[DNS Lookup] --> Server[(Web Server)]
    Caller -->|"VoIP call"| Codec[Voice→Packets] --> Broadband[Broadband Link] --> Callee

Exam takeaway: URL = address of a resource, VoIP = voice carried as IP data, Broadband = the high-speed always-on medium that makes both practical.