De-Broglie wavelength of an electron orbiting in the $n=2$ state of hydrogen atom is close to

(Given Bohr radius $=0.052 \mathrm{~nm}$ )

Which of the following options represent the variation of photoelectric current with property of light shown on the x-axis?

A photon and an electron (mass $m$ ) have the same energy $E$. The ratio ( $\lambda_{\text {photon }} / \lambda_{\text {electron }}$ ) of their de Broglie wavelengths is: ( $c$ is the speed of light)

An electron and an alpha particle are accelerated by the same potential difference. Let $$\lambda_e$$ and $$\lambda_\alpha$$ denote the de-Broglie wavelengths of the electron and the alpha particle, respectively, then:

If $$\phi$$ is the work function of photosensitive material in $$\mathrm{eV}$$ and light of wavelength of numerical value $$\lambda=\frac{h c}{e}$$ metre, is incident on it with energy above its threshold value at an instant then the maximum kinetic energy of the photo-electron ejected by it at that instant (Take $$h$$-Plank's constant, $$c$$-velocity of light in free space) is (in SI units):

The graph which shows the variation of $$\left(\frac{1}{\lambda^2}\right)$$ and its kinetic energy, $$E$$ is (where $$\lambda$$ is de Broglie wavelength of a free particle):

If $$c$$ is the velocity of light in free space, the correct statements about photon among the following are:

A. The energy of a photon is $$E=h v$$.

B. The velocity of a photon is $$c$$.

C. The momentum of a photon, $$p=\frac{h v}{c}$$.

D. In a photon-electron collision, both total energy and total momentum are conserved.

E. Photon possesses positive charge.

Choose the correct answer from the options given below:

The de Broglie wavelength associated with an electron, accelerated by a potential difference of 81 V is given by:

The maximum kinetic energy of the emitted photoelectrons in photoelectric effect is independent of:

The work functions of Caesium $$(\mathrm{Cs})$$, potassium $$(\mathrm{K})$$ and Sodium (Na) are $$2.14 ~\mathrm{eV}, 2.30 ~\mathrm{eV}$$ and $$2.75 ~\mathrm{eV}$$ respectively. If incident electromagnetic radiation has an incident energy of $$2.20 ~\mathrm{eV}$$, which of these photosensitive surfaces may emit photoelectrons?

The minimum wavelength of $$X$$-rays produced by an electron accelerated through a potential difference of $$V$$ volts is proportional to :

The light rays having photons of energy 4.2 eV are falling on a metal surface having a work function of 2.2 eV. The stopping potential of the surface is

The threshold frequency of a photoelectric metal is v₀. If light of frequency 4v₀ is incident on this metal, then the maximum kinetic energy of emitted electrons will be :

When two monochromatic lights of frequency, v and $${v \over 2}$$ are incident on a photoelectric metal, their stopping potential becomes $${{{V_s}} \over 2}$$ and V_s respectively. The threshold frequency for this metal is