Light of wavelength 5000,,mathop Alimits^o falling on a sensitive surface. If surface has rece

English

Gujarati

Hindi

11.Dual Nature of Radiation and matter

medium

Light of wavelength $5000\,\,\mathop A\limits^o $ falling on a sensitive surface. If the surface has received $10^{-7}\,J$ of energy, then the number of photons falling on the surface will be

A

$5\times 10^{11}$

B

$2.5\times 10^{11}$

C

$3\times 10^{11}$

D

none of these

Solution

Energy of one photon $=\frac{\mathrm{hc}}{\lambda}=4 \times 10^{-19}=\mathrm{E}$

$(n)$ $(\mathrm{E})=$ Energy $=10^{-7}$

$(n)$ $\left(4 \times 10^{-19}\right)=10^{-7}$

$\mathrm{n}=2.5 \times 10^{11}$

Standard 12

Physics

Share

Similar Questions

When wavelength of incident photon is decreased then

easy

Monochromatic light of wavelength $3000\, \mathring A $ is incident on a surface area $4\ cm^2$. If intensity of light is $150\, mW/m^2$, then rate at which photons strike the target is

medium

Monochromatic light of wavelength $667 \,\,nm$ is produced by a helium neon laser. The power emitted is $9 \,\,mW.$ The number of photons arriving per sec. on the average at a target irradiated by this beam is

medium

(AIPMT-2009)

If $2.5 \times 10^{-6\,} N$ average force is exerted by a light wave on a non-reflecting surface of $30\, cm ^{2}$ area during $40$ minutes of time span, the energy flux of light just before it falls on the surface is ……………… $W / cm ^{2}$

(Round off to the Nearest Integer)

(Assume complete absorption and normal incidence conditions are there)

medium

(JEE MAIN-2021)

The electrons are emitted in the photoelectric effect from a metal surface

easy