Which of the following statements is not true with respect to photoelectric effect -

1. The plot of kinetic energy of the photoelectrons against frequency of absorbed radiation gives a straight line parallel to x-axis

2. The plot of K.E. of the photoelectrons against frequency of absorbed radiation gives a straight line with slope equal to h and intercept to work function of metal

3. The plot of kinetic energy of the photoelectrons versus the intensity of incident radiation with constant frequency gives a straight line parallel to x-axis

4. When intensity of light is increased the number of photons ejected increases but the energies of these electrons are the same.

Using radiation of wavelength 3500 Å, it is observed that the maximum kinetic energy of the emitted photoelectrons is 1.6 eV for potassium. Calculate the work function of the metal. [h=6.626 x 10^-34 Js, 1 eV=1.6 x 10^-19 J]

1. 3 eV

2. 2.5 eV

3. 3.5 eV

4. 2 eV

The work function of a metal is 4.2 eV. If radiations of 2000 $A^0$ fall on the metal then the kinetic energy of the fastest photoelectron is 

1. 1.6 x 10^-19J 

2. 16 x 10¹⁰J 

3. 3.2 x 10^-19J 

4. 6.4 x 10^-10J 

Radial amplitude of electron wave can be represented by

1.  $\mathrm{R}\left(\mathrm{r}\right)$

2.  ${\mathrm{R}}^2\left(\mathrm{r}\right)$

3.  $4{\mathrm{\pi r}}^2$

4.  $4{\mathrm{\pi r}}^2{\mathrm{R}}^2\left(\mathrm{r}\right)$

In photoelectric effect, the kinetic energy of photoelectrons increases linearly with the:

1.  Wavelength of incident light.

2.  Frequency of incident light.

3.  Velocity of incident light.

4.  Atomic mass of an element.

Slope of ${\mathrm{V}}_0$ vs v curve is (where ${\mathrm{V}}_0$=stopping potential, v=subjected frequency)

1.  $\mathrm{e}$

2.  $\frac{\mathrm{h}}{\mathrm{e}}$

3.  $\mathrm{\varphi }$

4.  $\mathrm{h}$

According to Einstein's photoelectric equation, the graph between kinetic energy of

photoelectrons ejected and the frequency of the incident radiation is:

1.  

2.  

3.  

4.  

The photoelectric emission from a surface starts only when the light incident upon the surface has a certain minimum:

If ${\mathrm{\lambda }}_0$ and $\mathrm{\lambda }$ be the threshold wavelength and the wavelength of incident light, the velocity of photo-electrons ejected from the metal surface is:

1.  $\sqrt{\frac{2\mathrm{h}}{\mathrm{m}}\left({\mathrm{\lambda }}_0-\mathrm{\lambda }\right)}$

2.  $\sqrt{\frac{2\mathrm{hc}}{\mathrm{m}}\left({\mathrm{\lambda }}_0-\mathrm{\lambda }\right)}$

3.  $\sqrt{\frac{2\mathrm{hc}}{\mathrm{m}}\left(\frac{{\mathrm{\lambda }}_0-\mathrm{\lambda }}{{\mathrm{\lambda \lambda }}_0}\right)}$

4.  $\sqrt{\frac{2\mathrm{h}}{\mathrm{m}}\left(\frac{1}{{\mathrm{\lambda }}_0}-\frac{1}{\lambda }\right)}$

The ratio of slopes of ${\mathrm{K}}_{\max } \mathrm{vs}. \mathrm{v} \mathrm{and} {\mathrm{V}}_0 \mathrm{vs}. \mathrm{v}$ curves in photoelectric effect gives -

(v=frequency, ${\mathrm{K}}_{\max }$=maximum kinetic energy, ${\mathrm{V}}_0$ stopping potential):

1.  Charge of electron

2.  Planck's constant

3.  Work function

4.  The ratio of Planck's constant of electronic charge