Find the number of photons emitted per second by a $25$ watt source of monochromatic light of wavelength $6600 \mathring A$. What is the photoelectric current assuming $3 \%$ efficiency for photoelectric effect?
$\frac{25}{2} \times 10^{19} , 0.4\,amp$
$\frac{25}{4} \times 10^{19} , 6.2\,amp$
$\frac{25}{2} \times 10^{19} , 0.8\,amp$
None of these
The frequency of a photon, having energy $100eV$ is$(h = 6.6\,{10^{ - 34}}\,J{\rm{ - }}sec)$
Monochromatic light of frequency $6.0 \times 10^{14} \;Hz$ is produced by a laser. The power emitted is $2.0 \times 10^{-3} \;W$.
$(a)$ What is the energy of a photon in the light beam?
$(b)$ How many photons per second, on an average, are emitted by the source?
When light of a given wavelength is incident on a metallic surface, the minimum potential needed to stop the emitted photoelectrons is $6.0 V$. This potential drops to $0.6 V$ if another source with wavelength four times that of the first one and intensity half of the first one is used. What are the wavelength of the first source and the work function of the metal, respectively? $\left[\right.$ Take $\left.=\frac{h c}{c}=1.24 \times 10^{-6} Jm ^{-1}.\right]$
Which of the following is incorrect statement regarding photon
A monochromatic beam of light of wavelength $400\,nm$ incident normally upon a photosensitive surface ($25\%$ reflects and rest absorbs), produces a pressure of $5 \times 10^{-7}\,Nm^{-2}$ on it. If $0.1\%$ of the incident photons produce electrons then corresponding saturation current will be..............$\mu A$ (consider area of photosensitive surface $= 5\,cm^2$)