Duduli

Answer:- These are the waves having longest wave-length(of the order of 10⁶cm) existing on a.c. power lines.In homes we get a.c. power supply at 50Hz. Most  of the energy is confined to power line, very little is radiated into space.

Answer:- Waves belonging to this region are visible to human eye and possess wave-lengths lying in between 3.9×10^-⁵cm and 7.8 × 10^-⁵cm.These waves are emitted by incandescent bodies and are capable of effecting photographic plates.

Answer:- Since the electromagnetic wave is composed of varying electric and magnetic vectors at right angles to eachother, it is called electro-magnetic wave.

Answer:- Waves possessing wavelengths less than 10-¹⁰cm are called gamma (γ) rays.They are produced due to the transition of nuclides from a higher quantum state to a lower one and from conversation of matter into radiation.They are highly penetrating.