A copper ball of radius 1, cm and work functi | vedclass

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

Question

(A) The energy of the incident photon is given by $E = \frac{hc}{\lambda} = \frac{12400}{\lambda(	ext{in } \mathring{A})} \, eV$.Substituting $\lambd

Vedclass · Accepted Answer

$5.5 	imes 10^{-13}\, C$

Vedclass · Answer

(A) The energy of the incident photon is given by $E = \frac{hc}{\lambda} = \frac{12400}{\lambda(	ext{in } \mathring{A})} \, eV$.Substituting $\lambda = 2500\, \mathring{A}$,we get $E = \frac{12400}{2500} = 4.96\, eV$.The maximum kinetic energy of the emitted electrons is $K_{max} = E - \Phi$,where $\Phi = 4.47\, eV$ is the work function.$K_{max} = 4.96 - 4.47 = 0.49\, eV$.As the ball emits electrons,it becomes positively charged,creating a potential $V$ that stops further emission. The stopping potential $V$ is equal to $K_{max}/e$,so $V = 0.49\, V$.The potential of a charged sphere is $V = \frac{1}{4\pi\epsilon_0} \frac{Q}{r} = k \frac{Q}{r}$,where $k = 9 	imes 10^9\, N\cdot m^2/C^2$ and $r = 0.01\, m$.$0.49 = \frac{9 	imes 10^9 	imes Q}{0.01}$.$Q = \frac{0.49 	imes 0.01}{9 	imes 10^9} = \frac{0.0049}{9 	imes 10^9} \approx 5.44 	imes 10^{-13}\, C$.Rounding to the nearest option,$Q = 5.5 	imes 10^{-13}\, C$.

Similar Questions

In a photoelectric experiment,light of energy $2.48 eV$ irradiates a photosensitive material. The stopping potential was measured to be $0.5 V$. The work function of the photosensitive material is: (in $eV$)

When a photon of energy $6 \, eV$ is incident on a metal surface,the maximum kinetic energy of the emitted photoelectrons is $4 \, eV$. The value of the stopping potential is .......... $V$.

Let $K_1$ be the maximum kinetic energy of photoelectrons emitted by light of wavelength $\lambda_1$ and $K_2$ be the maximum kinetic energy corresponding to wavelength $\lambda_2$. If $\lambda_1 = 2\lambda_2$,then:

The photoelectric cut-off voltage in a certain experiment is $1.5 \ V$. What is the maximum kinetic energy of the emitted photoelectrons?

Albert Einstein was awarded the Nobel Prize in Physics for his work on

Vedclass Test Series

Exam Paper Generator

Online Exam Module