10th Class Physics: Electromagnetic Waves

Electromagnetic Radiation

• Electromagnetic radiation is a form of energy that travels through space and includes heat, light, X-rays, and microwave energy.
• It exhibits wavelike properties, consisting of two waves oscillating perpendicular to each other: an oscillating magnetic field and an oscillating electric field.

Basic Properties of Waves

• A wave has a trough (lowest point) and a crest (highest point).
• Amplitude is the vertical distance between the tip of a crest and the wave's central axis, measuring the amount of energy transferred by a wave.
• Increasing the wavelength by a factor of 10 decreases the frequency to 1/10 of its initial value.

Period

• A wave's period is the length of time it takes for one wavelength to pass by a given point in space.
• The period (T) is the reciprocal of the wave's frequency (f): T = 1/f.
• The units of period are seconds (s).

Electromagnetic Spectrum

• The electromagnetic spectrum is the range of all types of electromagnetic radiation.
• The spectrum includes radio waves, microwaves, infrared light, ultraviolet light, X-rays, and gamma-rays.
• Radiation is energy that travels and spreads out as it goes, and examples include visible light from a lamp and radio waves from a radio station.

Types of Electromagnetic Radiation

• Radio waves: used for TV and mobile communication, can also be emitted by gases and stars in space.
• Microwaves: used for cooking, also used by astronomers to determine the structure of nearby galaxies and stars.
• Infrared: used in night vision goggles.

Wavelength and Frequency

• Wavelength is the horizontal distance between two consecutive troughs or crests.
• Frequency is the number of full wavelengths that pass by a given point in space every second, measured in Hertz (Hz).
• Wavelength and frequency are inversely proportional: shorter wavelength means higher frequency, and vice versa.
• The relationship between wavelength and frequency is given by the equation: λν = c, where c is the speed of light (3.00 × 10^8 m/s).

Test your understanding of electromagnetic waves, a fundamental concept in physics. This quiz covers the basics of electromagnetic radiation, its forms, and applications.