Dual Nature of ...

Assertion In photoelectric effect, on increasing the intensity of light, both the number of electrons emitted and kinetic energy of each of them get increased but photoelectric current remains unchanged.
Reason The photoelectric current depends only on wavelength of light.

Assertion Standard optical diffraction can not be used for discriminating between different X-ray wavelengths.
Reason The grating spacing is not of the order of X-ray wavelengths.

Assertion The threshold frequency of photoelectric effect supports the particle nature of sunlight.
Reason If frequency of incident light is less than the threshold frequency, electrons are not emitted from metal surface.

Assertion In photo emissive cell inert gas is used.
Reason Inert gas in the photo emissive cell gives greater current.

Assertion X-rays cannot be diffracted by means of grating.
Reason X-rays do not obey Bragg\'s law.

Assertion X-rays can penetrate through the flesh but not through the bones.
Reason The penetrating power of X-rays depends on voltage.

Assertion Intensity of X-rays can be controlled by adjusting the filament current and voltage.
Reason The intensity of X-rays does not depend on number of X-ray photons emitted per second from the target.

Assertion Soft and hard X-rays differ in frequency as well as velocity.
Reason The penetrating power of hard X-rays is more than the penetrating power of soft X-rays.

Assertion Penetrating power of X-rays increases with the increasing the wavelength.
Reason The penetrating power of X-rays increases with the frequency of X-rays.

Assertion X-rays are used for studying the structure of crystals.
Reason The distance between the atoms of crystals is of the order of wavelength of X-rays.