Why is exposure to X-ray injurious to health but exposure to visible light is not, when both are electromagnetic waves?

According to Maxwell, when charges emit electromagnetic waves?

Which phenomena shows both particle and wave nature of electromagnetic waves and electron?

Which of the given phenomenon is based on the fact that light waves are transverse electromagnetic waves?

Two small boats are 10m apart on a lake. Each pops up and down with a period of 4.0 seconds due to wave motion on the surface of water. When one boat is at its highest point, the other boat is its lowest point. Both boats are always within a single cycle of the waves. The speed of the waves is:

Electromagnetic waves with wavelength (i) lambda_(1) is used in satellite communication. (ii) lambda_(2) is used to kill germs in water purifies. (iii) lambda_(3) is used to detect leakage of oil in underground pipelines. (iv) lambda_(4) is used to improe visibility in runways during fog and mist conditions. Identify and name the part of electromagnetic spectrum to which these radiations belong.

There are two sources of light,each emitting with a power of 100W.One emits X-rays of wavelength 1 nm and the other visible light at 500 nm.Find the ratio of number of photons of X-rays to the photon of visible light of the given wavelength?

(a) When monochromatic light is incident on a surface separating two media, the reflected and refracted light both have the same frequency as the incident frequency. Explain why? (b) When light travels from a rarer to a denser medium, the speed decreases. Does the reduction in speed imply a reduction in the energy carried by the light wave? (c) In the wave picture of light, intensity of light is determined by the square of the amplitude of the wave. What determines the intensity of light in the photon picture of light

Frequency of various radiations are given as f_(v) to Visible light, f_(r )to Radio waves f_(UV)to Ultra Violet waves Then which of following is true ?