Dual Nature of ...

A light of wavelength $$ \lambda$$ is incident on a metal sheet of work function $$ \phi = 2eV$$. The  wavelength $$ \lambda$$ varies with time as $$ \lambda = 3000 + 40t,   where   \lambda$$ is in and t is in second. The power incident on metal sheet is constant at 100 W. This signal is switched on and off for time intervals of 2 minutes and 1 minute respectively. Each time the signal is switched on, the $$ \lambda$$ start from an initial value of 3000. The metal plate is grounded and electron clouding is negligible. The efficiency of photoemission is 1%$$ (hc = 12400 eV)$$. The time after which photo-emission will stop is 

The phenomenon of ejection of electrons from the surface of metal, when light of a suitable frequency falls on, it is called

A particle of mass $$'m\ '$$ is projected from ground with velocity $$'u\ '$$ making an angle $$'\theta \ '$$ with the vertical. The de-Broglie wavelength of the particle at the highest point is 

If the shortest wavelength of the continuous X-ray spectrum coming out of a Coolidge tube is $$0.01nm$$, then the de Broglie wavelength of the electron reaching the target metal in the Coolidge tube is approximately
$$ (hc = 12400 e VA, h = 6.63 \times 10^{-34} $$ in  MKS, mass  of  electron$$  = 9.1 \times 10^{-31}kg)$$

If we assume that penetrating power of any radiation/particle is inversely proportional to the De-broglie wavelength of the particle, then

Two particles of masses $$m$$ and $$2m$$ have equal kinetic energies. Their de Broglie wavelengths are in the ratio of :

Will the radiation from a 50 kW, 100 MHz FM station expose the film?

Electron and proton are accelerated through one volt of potential difference, the ratio of their wavelengths is equal to:

What is de Broglie wavelength associated with an $$e^{-}$$ accelerated through potential difference = 100 kV?

de Broglie relation is true  for