Explanation

• Full Form: Structured Query Language
• SQL is the standard language used to store, retrieve, update, and manage data in relational databases.

Additional information:

• Designed by: Donald D. Chamberlin & Raymond F. Boyce
• First appeared: 1974
• Latest ISO Standard: SQL:2016 (December 2016)
• Main SQL Commands: SELECT, INSERT, UPDATE, DELETE, CREATE

Last verified on 22-07-2026

Explanation

• Alt + Shift + F1 / Shift + F11 → Insert a new worksheet

Additional information:

• Shift + F10 → Open shortcut/context menu
• Ctrl + Page Up → Previous worksheet
• Ctrl + Page Down → Next worksheet

Last verified on 15-07-2026

Explanation

• Blue light has the shortest wavelength.
• In the visible spectrum, wavelength decreases from red to violet.

Additional information:

• Red light rays have the lowest frequency and highest wavelength value.

Last verified on 10-06-2026

Explanation

• Light Year is the distance that light can travel in one year.
• The distance light travels in one year is known as light year.
• 1 light year is equal to 9.5 x 10¹²km.

Last verified on 30-03-2026

Explanation

• LAN stands for Local Area Network.
• It is a network that connects devices within a limited geographical area.
• LAN is commonly used in homes, schools, laboratories, university campuses, and office buildings.
• It provides high-speed communication and resource sharing between connected devices.

Additional information:

• MAN: Metropolitan Area Network – Covers a city or metropolitan area
• WAN: Wide Area Network – Covers a large geographical area (countries/continents)

Last verified on 07-07-2026

Explanation

• Sir James Chadwick discovered the neutron in 1932.
• He was a British physicist.
• His discovery completed the basic picture of the atomic nucleus.
• He received the Nobel Prize in Physics in 1935 for this discovery.

Additional information:

• J. J. Thomson – Electron (1897)
• Ernest Rutherford – Atomic nucleus (1911) and Proton (1917)

Last verified on 03-07-2026

Explanation

• Karl Landsteiner discovered the ABO Blood Group System in 1900.
• He was an Austrian scientist and physician.
• His discovery made safe blood transfusions possible.
• He received the Nobel Prize in Physiology or Medicine in 1930 for his work.

Last verified on 01-07-2026

Explanation

• The correct phrase is "prefer tea to coffee."
• We use "prefer + noun + to + noun" when comparing two choices.
• Example: I prefer tea to coffee.

Last verified on 01-07-2026

Explanation

• Mass and Length are base quantities in SI units.
• Length SI Unit: meter (m)
• Mass SI Unit: kilogram (kg)

Additional information:

Base Quantities in SI System:

• Time (second)
• Electric current (ampere)
• Temperature (kelvin)

Last verified on 16-06-2026

Explanation

• The audible range of a normal human ear is 20 Hz to 20,000 Hz (20 kHz).
• Sounds below this range are called infrasound,
• Sounds above it are called ultrasound. 
• Lower limit: 20 Hz (deep rumbles)
• Upper limit: 20,000 Hz (high-pitched squeaks)

Additional information

• Adult change: The upper limit often drops to 15,000–17,000 Hz as people get older. 
• Unit of frequency: Hertz (Hz)

Last updated 27-07-2026 by NA