SP | MCQs

Explanation

• Asteroids are irregularly shaped solid objects composed primarily of rocks and metals.
• They are found mainly in the asteroid belt between Mars and Jupiter.

Explanation

• Apollo 11 was the mission that successfully landed astronauts.
• Neil Armstrong and Buzz Aldrin on the moon on July 20, 1969.

Explanation

• If a human-made (artificial) body moves around a celestial body it is called an artificial satellite.
• Artificial satellites are objects placed into orbit around celestial bodies by humans for purposes such as communication, weather monitoring, and scientific research.

Explanation

A satellite is an object that orbits a larger celestial body, such as a planet or star.

Examples:

• Moons (natural satellites) that orbit planets
• Artificial satellites (like the International Space Station) that orbit Earth

Explanation

• The speed of sound in aluminium is approximately 6420 meters per second.
• It is significantly faster than the speed of sound in air due to aluminium's higher density and elastic properties.

The speed of sound in different materials:

• Air: 332 m/s
• Sea water: 1530 m/s
• Lead: 2160 m/s
• Gold: 3240 m/s
• Brick: 3650 m/s
• Copper: 4760 m/s
• Glass: 5100 m/s
• Aluminium: 6420 m/s

Explanation

• The speed of sound is maximum in gold, with a value of approximately 3240 meters per second (m/s).

The speed of sound in different materials:

• Air: 332 m/s
• Sea water: 1530 m/s
• Lead: 2160 m/s
• Gold: 3240 m/s
• Brick: 3650 m/s
• Copper: 4760 m/s
• Glass: 5100 m/s
• Aluminium: 6420 m/s

Explanation

• The speed of sound in aluminium is approximately 6420 meters per second.
• It is significantly faster than the speed of sound in air due to aluminium's higher density and elastic properties.

The speed of sound in different materials:

• Air: 332 m/s
• Sea water: 1530 m/s
• Lead: 2160 m/s
• Gold: 3240 m/s
• Brick: 3650 m/s
• Copper: 4760 m/s
• Glass: 5100 m/s
• Aluminium: 6420 m/s

Explanation

• The speed of sound is minimum in gases because the particles are farthest apart, resulting in a slower transmission of vibrations.
• In gases, the speed of sound is approximately 343 meters per second at room temperature and atmospheric pressure.

Explanation

• The flash of light from lightning is a form of electromagnetic radiation, and as such, it travels at the speed of light.
• It is denoted by the letter c.

It is equal to:

• 3 x 10^8 meters per second (m/s) in scientific notation
• 300,000 kilometers per second (km/s) in metric units
• 186,282 miles per second (mi/s) in imperial units

Explanation

• Specular (Regular) reflection occurs when a parallel beam of light hits a smooth surface, such as a mirror.
• It is reflected as parallel rays, maintaining its original direction and intensity.

Examples:

• Polished metal surfaces
• Calm surface of a lake
• Calm water and mirrors