When radiation of wavelength lambda is incide | vedclass

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

Question

(B) The Einstein's photoelectric equation is given by $eV_0 = \frac{hc}{\lambda} - \phi_0$,where $\phi_0 = \frac{hc}{\lambda_0}$ and $\lambda_0$ is th

Vedclass · Accepted Answer

$4 \lambda$

Vedclass · Answer

(B) The Einstein's photoelectric equation is given by $eV_0 = \frac{hc}{\lambda} - \phi_0$,where $\phi_0 = \frac{hc}{\lambda_0}$ and $\lambda_0$ is the threshold wavelength.For the first case: $e(4.8) = \frac{hc}{\lambda} - \phi_0 \quad ... (i)$For the second case: $e(1.6) = \frac{hc}{2\lambda} - \phi_0 \quad ... (ii)$Dividing equation $(i)$ by equation $(ii)$:$\frac{4.8}{1.6} = \frac{\frac{hc}{\lambda} - \phi_0}{\frac{hc}{2\lambda} - \phi_0}$$3 = \frac{\frac{hc}{\lambda} - \phi_0}{\frac{hc}{2\lambda} - \phi_0}$$3 \left( \frac{hc}{2\lambda} - \phi_0 \right) = \frac{hc}{\lambda} - \phi_0$$\frac{3hc}{2\lambda} - 3\phi_0 = \frac{hc}{\lambda} - \phi_0$$\frac{3hc}{2\lambda} - \frac{hc}{\lambda} = 2\phi_0$$\frac{hc}{2\lambda} = 2\phi_0 \implies \phi_0 = \frac{hc}{4\lambda}$Since $\phi_0 = \frac{hc}{\lambda_0}$,we have $\frac{hc}{\lambda_0} = \frac{hc}{4\lambda}$.Therefore,the threshold wavelength $\lambda_0 = 4\lambda$.

When radiation of wavelength $\lambda$ is incident on a metallic surface,the stopping potential is $4.8 \ V$. If the surface is illuminated with radiation of double the wavelength,then the stopping potential becomes $1.6 \ V$. The threshold wavelength for the surface is:

Similar Questions

Methanogens belong to:

If a change in current of $0.01 ~A$ in one coil produces a change in magnetic flux of $2 \times 10^{-2} ~Wb$ in the other coil,then the mutual inductance of the two coils in henry is (in $~H$)

The radius of a circular plate is increasing at the rate of $0.01 \text{ cm/s}$ when the radius is $12 \text{ cm}$. Then,the rate at which the area increases,is

Three bodies,a ring,a solid cylinder,and a solid sphere,roll down the same inclined plane without slipping. They start from rest. The radii of the bodies are identical. Which of the bodies reaches the ground with maximum velocity?

If $\frac{x^3}{(2 x-1)(x+2)(x-3)} = A+\frac{B}{2 x-1}+\frac{C}{x+2}+\frac{D}{x-3}$,then $A$ is equal to

Vedclass Test Series

Exam Paper Generator

Online Exam Module