Waves

• An anemometer has a spinning wheel.
• The stronger the wind blows, the faster the wheel rotates.
• The anemometer counts the number of rotations which is used to calculate the wind speed.

• An anemometer has a spinning wheel.
• The stronger the wind blows, the faster the wheel rotates.
• The anemometer counts the number of rotations which is used to calculate the wind speed.

• It is in the form of a wooden hollow rectangular box with a hook at one end and a pulley at the other end.

A level of the atmosphere which is composed partly of electrons and positive ions is called the ionosphere.

• The ionosphere is a region in the Earth's upper atmosphere, extending from about 50 km to 1000 km above the surface.
• It overlaps with the mesosphere, thermosphere, and exosphere.
• This layer is ionized by solar radiation, which knocks electrons off atoms and molecules, creating ions.
• These free electrons and ions significantly affect the propagation of radio waves.
• The ionosphere is also where auroras (the Northern and Southern Lights) occur.

• A normal human eye can see electromagnetic radiation between 390 nm to 750 nm wavelength.
• Ultraviolet rays = 10nm - 40nm
• X-rays = 0.01mm - 10nm

Hence option (a) will be the correct answer.

• This is because solids have a higher elasticity than liquids and gasses, which allows sound waves to travel faster through them.
• The exact speed of sound in a solid depends on the material and its properties, such as density, stiffness, and temperature.
• For example, the speed of sound is approximately 6320 m/s meters per second in Aluminium.

• This is because solids have a higher elasticity than liquids and gasses, which allows sound waves to travel faster through them.
• The exact speed of sound in a solid depends on the material and its properties, such as density, stiffness, and temperature.