Explanation

• Spirogyra, Volvox, and Chlamydomonas are all types of algae.
• They are simple, photosynthetic organisms.
• They belong to the Kingdom Protista.
• They are commonly found in freshwater environments.

Last verified on 06-11-2026

Explanation

• Ephedra is a genus of gymnosperms belonging to the division Gnetophyta.
• It is a seed-producing plant with naked seeds.
• It is commonly found in dry and desert regions.

Last verified on 06-11-2026

Explanation

• Pollen grains of many gymnosperms, especially Pinus, have two air sacs called sacci.
• These wings help pollen grains travel through the air.
• Gymnosperms produce naked seeds because their ovules are not enclosed within an ovary.

Last verified on 06-11-2026

Explanation

• During the daytime, plants require Carbon Dioxide (CO2) for photosynthesis.
• Which is the process by which they produce glucose and oxygen.

Last updated by NA on 05-11-2026

Explanation

• Mars is known as the Red Planet due to its reddish appearance.
• Its surface contains iron oxide (rust) which gives it a red color.
• It is the 4th planet from the Sun in the solar system.
• Mars has two small moons: Phobos and Deimos.
• Mars is often called the “planet of future exploration”.

Last updated by NA on 05-11-2026

Explanation

• Stayed for 14 days at Quba during the migration to Madinah in 1 AH (622 CE).
• Stayed at the house of Hazrat Kulthum bin al-Hidm (رضي الله عنه).
• Laid the foundation of Masjid Quba, the first mosque in Islam.

Last updated by NA on 05-11-2026

Explanation

• Wilhelm Conrad Rontgen discovered X-rays
• He was discovered on 8 November 1895.
• He got the Nobel Prize in Physics in 1901.

Additional questions

• The penetrating power of X-rays depends on their frequency

Last updated by NA on 05-11-2026

Explanation

• Inventors: Montgolfier brothers (Joseph-Michel and Jacques-Étienne).
• First public demonstration: 4 June 1783, Annonay, France.
• First passenger flight: 1783, near Paris.
• Known as: Pioneers of human flight.

Last updated by NA on 04-11-2026

Explanation

• The average distance from the Earth to the Sun is approximately 150 million kilometers.
• It is also called 1 astronomical unit (or AU).

Last updated by NA on 04-11-2026

Explanation

Formula of parallel plate capacitor:

C = ε₀ x A / d

Where:

C = capacitance = 1 F

ε₀ = permittivity of free space = 8.85 x 10⁻¹² F/m

A = area of plates = ?

d = distance between plates = 1 mm = 0.001 m = 10⁻³ m

We need A:

A = C x d / ε₀

Put values:

A = 1 x 10⁻³ / 8.85 x 10⁻¹²

A = 10⁻³ / 8.85 x 10⁻¹²

A = (1 / 8.85) x 10⁹

A = 0.1129 x 10⁹

A = 1.129 x 10⁸

A ≈ 1.13 x 10⁸ m²

Last verified on 03-11-2026