Origin Of Quantum Mechanics MCQ Level – 1 - Physics MCQ

The energy E and momentum p of photon is given by E = hv and  p = h/λ, the velocity of photon will be :

In the figure six lines of emission spectrum are shown. Which of them will be absent in the absorption spectrum.

A charge particle q₀ of mass m₀ is projected along the y-axis at t = 0 from origin with a velocity V₀. If uniform electric field E₀ also exists along the x-axis, then the time at which de-Broglie wavelength of the particle becomes half of the initial value is :

What voltage must be applied to an electron microscope to produce electrons of 

In X-rays production an electron accelerated with voltage V strikes a metal target. For which of the following voltages X-rays of minimum wavelength will be produced :

In the photoelectric, if we use a monochromatic light, the I-V curve is as shown. If work function of the metal is 2eV, estimate the power of light used. (Assume efficiency of photo emission = 10^–3 % i.e. number of photoelectrons emitted are 10^–3 % of number of photons incident on metal.)

In Davisson-Germer experiment the relation between the angle of diffraction θ and the grazing angle φ is.