Assuming photoemission takes place,the factor | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(D) According to Einstein's photoelectric equation: $\frac{hc}{\lambda} = W_0 + \frac{1}{2}mv_{\max}^2$. Let the initial wavelength be $\lambda_1 = \l

Vedclass · Accepted Answer

$< \frac{1}{2}$

Vedclass · Answer

(D) According to Einstein's photoelectric equation: $\frac{hc}{\lambda} = W_0 + \frac{1}{2}mv_{\max}^2$. Let the initial wavelength be $\lambda_1 = \lambda$ and the final wavelength be $\lambda_2 = 4\lambda$. The maximum kinetic energy is given by $K_{\max} = \frac{hc}{\lambda} - W_0$. Since $K_{\max} = \frac{1}{2}mv_{\max}^2$,we have $v_{\max} = \sqrt{\frac{2}{m} (\frac{hc}{\lambda} - W_0)}$. When $\lambda$ increases to $4\lambda$,the energy of the incident photon $\frac{hc}{4\lambda}$ decreases. Since $K_{\max}$ decreases,$v_{\max}$ also decreases. Let the new velocity be $v'$. Then $v' = \sqrt{\frac{2}{m} (\frac{hc}{4\lambda} - W_0)}$. Comparing $v'$ with $v_{\max}$: $v' = \sqrt{\frac{1}{4} \frac{2hc}{\lambda} - \frac{2W_0}{m}} = \sqrt{\frac{1}{4} v_{\max}^2 - \frac{3W_0}{2m}}$. Since $\frac{1}{4} v_{\max}^2 - \frac{3W_0}{2m} Thus,the factor by which the velocity changes is less than $\frac{1}{2}$.

Assuming photoemission takes place,the factor by which the maximum velocity of the emitted photoelectrons changes when the wavelength of the incident radiation is increased four times,is

Similar Questions

In the photoelectric effect,a graph is plotted between the maximum kinetic energy of electrons and the frequency of incident photons. The slope of this curve will be .......

In a photoemissive cell with exciting wavelength $\lambda$,the fastest electron has speed $v$. If the exciting wavelength is changed to $\frac{3\lambda}{4}$,the speed of the fastest emitted electron will be

Assuming photoemission to take place,the factor by which the maximum velocity of the emitted photoelectrons changes when the wavelength of the incident radiation is increased four times,is

Explain Einstein's photoelectric effect and derive Einstein's photoelectric equation.

Vedclass Test Series

Exam Paper Generator

Online Exam Module