Electromagnetic Waves Questions and Answers for Viva

Answer-1: Electromagnetic waves are the waves that are produced because of the fast oscillation or vibration between an electric field and a magnetic field. In other words, they are formed when electric fields come in contact with magnetic fields. That is why it got the name Electro-Magnetic. EM waves are the alternate name for electromagnetic waves.

Answer-2: Electromagnetic waves can even travel in a vacuum with a stable velocity of 3 × 10⁸ m/s.

Answer-3: Electromagnetic waves travel in a straight line at the speed of light unless influenced by a medium. They can travel through a vacuum as well as various materials.

Answer-4: Electromagnetic waves are split into a wide range of frequencies. It is known as the electromagnetic spectrum, there order in increasing frequencies is, Radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays.

Answer-5: They have an inverse relationship: as the wavelength increases, the frequency decreases, and vice versa. This is described by the equation: c = λ?, where c is the speed of light, λ(lambda) is the wavelength, and ? is the frequency.

Answer-6: Antennas convert electrical signals into electromagnetic waves for transmission and vice versa for reception.

Answer-7: Various frequencies of radio waves are used for television and FM and AM radio broadcasts, military communications, mobile phones, ham radio, wireless computer networks, and numerous other communications applications.

Answer-8: Infrared rays are used to keep the plants warm. Infrared rays absorb the greenhouse gases in the atmosphere more compared to UV rays, X rays and radio waves, and cause the temperature of the earth to rise, resulting in a greenhouse effect. That is why it is used in the greenhouse to keep the plants warm.

Answer-9: Y rays are the electromagnetic waves which have the largest penetrating power. Its frequency ranges between 3 × 10⁸ Hz to 5 × 10²² Hz.

Answer-10: Ozone Layer absorbs all the harmful ultraviolet rays and protects the earth from their ill effects

Answer-11: The radiation is ultraviolet radiation. The frequency range of UV rays is 10¹⁵ Hz to 10¹⁷ Hz.

Answer-12: Microwaves are used in microwave ovens, telecommunications, satellite communication, and radar systems.

Answer-13: Infrared radiation is used in night vision technology, remote controls, thermal imaging, and cooking.

Answer-14: Visible light enables vision, photography, illumination, and optical communications through fiber optics.

Answer-15: Ultraviolet radiation can cause sunburn, skin aging, and potentially skin cancer. However, it is also used in sterilization and fluorescent lighting.

Answer-16: X-rays are used in medical imaging to visualize bones and internal structures, diagnose fractures, detect tumors, and monitor medical treatments.

Answer-17: Gamma rays are highly penetrative and can cause severe damage to living tissues, leading to radiation sickness and an increased risk of cancer.

Answer-18: Electromagnetic shielding involves the use of materials that absorb or reflect electromagnetic waves, protecting sensitive electronics or preventing interference.

Answer-19: Electromagnetic induction is the process of generating an electromotive force (emf) in a conductor by varying the magnetic field around it, utilized in generators and transformers.

Answer-20: Polarizing filters selectively transmit light waves with a specific polarization orientation, commonly used in sunglasses, photography, and liquid crystal displays (LCDs).