Explanation

• Because sound is just vibrating air, space has no air to vibrate and therefore no sound in a vacuum.
• Sound waves below 20 Hz are known as infrasound.
• Sound waves above 20 kHz are known as ultrasound.

Sound waves transmit a medium such as a gas, liquid, or solid.

• The speed of sound in air is about 343 meters per second.
• The sound travels at 1,481 m/s in water.
• The speed of sound in a vacuum is zero meters per second.

Last verified on 07-06-2026

Explanation

Ethiopia Capital is Addis Ababa.

Ethiopia Currency is Birr.

Ethiopia official language is Amharic.

Ethiopia located is in Continent Africa.

Ethiopia Primary Religion is Islam, Christianity.

Ethiopia Head of Govt. is Prime Minister – Abiy Ahmed.

Ethiopia Parliament called Federal Council And House Of Representative.

Tricks for Remember

Last verified on 07-06-2026

Explanation

• George Washington was the first President of the USA.
• He was serving from 1789 to 1797.
• He is often called the "Father of His Country" for his leadership in the founding of the United States.

Additional information:

The short list of Presidents of USA:

• 1st. George Washington
• 2nd. Adams John Adams
• 3rd. Thomas Jefferson
• 15th. James Buchanan
• 16th. Abraham Lincoln
• 17th. Andrew Johnson
• 44th. Barack Obama
• 45th. Donald Trump
• 46th. Joe Biden
• 47th. Donald Trump (Current)

Last verified on 07-06-2026

Explanation

• The Arctic is the shortest ocean in the world.

Additional information:

• The Pacific is the largest ocean in the world.
• 71% of Earth's surface is covered by ocean.
• The warmest ocean in the world is the Indian ocean.
• The hottest ocean area is the Persian Gulf.
• Diamantina Trench is the deepest place in the Indian ocean.
• Country Jordon has no ocean.

The five major oceans listed by size from largest to smallest are the:

1. The Pacific Ocean
2. The Atlantic Ocean
3. The Indian Ocean
4. The Southern Ocean
5. The Arctic Ocean

Last verified on 07-06-2026

Explanation

• First Governor: Zahid Husain
• Term: June 1948 – July 1953

Additional information:

• First Female Governor: Dr. Shamshad Akhtar
• Year of Female Governor Appointment: 2006
• Headquarters: Karachi, Pakistan

Last verified on 16-01-2026

Explanation

• The Mangla Dam is situated on the Jhelum River.
• It is the seventh-largest dam in the world.
• Construction was started in 1961.
• It was completed in 1967.
• It has 5 tunnels and a power station.

Last verified on 07-06-2026

Explanation

• Plan Name: First Five-Year Plan
• Duration: 1955–1960
• Country: Pakistan
• Main Focus: Education, agriculture, industrial development
• Objective: Economic and social development

Additional information:

• First Five-Year Plans (1955–1960)
• Second Five-Year Plans (1960–1965)
• Third Five-Year Plans (1965–1970)
• Fourth Five-Year Plans (1970–1975)
• Fifth Five-Year Plans (1978–1983)
• Sixth Five-Year Plan (1983–88)
• Seventh Five-Year Plan (1988–93)
• Eighth Five-Year Plan (1993–98)

Last verified on 17-05-2026

Explanation

• Alexander Fleming discovered Penicillin
• At St. Mary's Hospital in London
• In September 1928.
• First true antibiotic used to treat bacterial infections.
• First patient treated was Albert Alexander, a 43-year-old policeman, on 12 February 1941

Last updated by NA on 23-April-2026

Explanation

• The smallest province of Pakistan by area is KPK.
• Balochistan is the largest province of Pakistan by area.
• Area wise second largest province of Pakistan is Punjab.

Last verified on 30-03-2026

Explanation

Surface area = 4πr², Volume = 4/3πr³.  

Surface area is just derivative of volume w.r.t r.

2πr is circumference of a circle, not volume at all.

Last verified on 07-06-2026