Explanation

• An electric generator is a device that converts mechanical energy into usable electrical energy.
• This process is based on the principle of electromagnetic induction.
• Discovered in 1831 by British scientist Michael Faraday.

Last verified on 27-04-2026

Explanation

• Silica (SiO₂) is the main component of glass.
• It providing its transparency and hardness.
• It forms a network structure when melted, giving glass its solid yet brittle nature.

Last verified on 07-06-2026

Explanation

• Momentum (p = mv): If velocity doubles, momentum also doubles.
• Kinetic Energy (KE = ½mv²): If velocity doubles, KE becomes four times.

Last verified on 07-06-2026

Explanation

• Short-sightedness is called Myopia.
• It is corrected by a concave lens.
• This lens is thin in the center and thick at edges.
• It helps light focus on the retina correctly.
• Without correction, distant objects look blurred.

Additional information:

• Long-sightedness is called Hypermetropia.
• It is corrected by a convex lens.
• This lens is thick in the center and thin at edges.
• It helps light focus on the retina properly.
• Without correction, near objects look blurred.

Last verified on 07-06-2026

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