Explanation

• Driven harmonic oscillator is a system undergoing forced vibration.
• In forced vibrations, an external periodic force continuously acts on the system.
• The system oscillates with the frequency of the applied force.
• This differs from free oscillations, where no external force acts.

Last verified on 05-06-2026

Explanation

• He–Ne laser is a four-level laser system.
• It uses a mixture of helium and neon gases as the active medium.
• Four-level lasers are more efficient because population inversion is easier to achieve.
• Ruby laser is a three-level laser.

Last verified on 05-06-2026

Explanation

• The body cannot return to its original position when stress exceeds the elastic limit.
• Beyond the maximum elastic value, the material undergoes permanent deformation.
• Even after removing the stress, the original shape is not fully recovered.
• This behavior is called plastic deformation.

Last verified on 05-06-2026

Explanation

• The semi-major axis and the time period are related by Kepler's Third Law (Law of Periods).
• It states that the square of a planet's orbital period is proportional to the cube of its semi-major axis.
• Larger orbits take longer to complete.
• This law helps determine planetary distances and orbital periods.

Last verified on 05-06-2026

Explanation

1. ∂/∂x (x + 3y) = 1  
2. ∂/∂y (y - 2z) = 1  
3. ∂/∂z (x + mz) = m  

Explanation

• The Earth’s circumference at the equator is about 40,075 km (24,901 miles).
• Measured through the poles, it is slightly smaller: 40,008 km (24,860 miles).
• The difference is due to the equatorial bulge caused by Earth's rotation.
• Diameter: ~12,756 km (7,926 miles).
• Age of Earth: ~4.453 billion years.

Last verified on 31-03-2026

Explanation

• The largest planet in our solar system is Jupiter.
• 5th planet
• 79 known moons (Maximum number of moons)
• The Great Red Spot is a prominent feature
• Giant planet and the fastest-rotating planet 
• Rotates approximately once every 10 hours.
• Age is about 4.603 billion years.

Additional information

• Mercury is the smallest planet of the solar system.

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Last updated 07-09-2026 by NA

Explanation

• Satellites and the Moon move in an elliptical orbit around Earth.
• Their distance from Earth changes at different points in the orbit.
• The farthest point from Earth is given a special scientific name called apogee.
• The closest point has a different name called perigee.

Last verified on 31-05-2026

Explanation

• Earth moves around the Sun in an elliptical orbit.
• Because of this, the distance between Earth and Sun changes during the year.
• The point where Earth is closest to the Sun is called perihelion.
• This occurs in early January every year.

Last verified on 31-05-2026

Explanation

• A cream separator works on the principle of centrifugal force.
• When milk spins rapidly, heavier and lighter components separate.
• The heavier skimmed milk moves outward.
• The lighter cream stays closer to the center.

Last verified on 31-05-2026