Home
Class 12
PHYSICS
Any radiation in the ultraviolet region ...

Any radiation in the ultraviolet region of hydrogen spectrum is able to eject photoelectrons from a metal. What should be the maximum value of threshold frequency for the metal?

A

`3.288times10^(15)Hz`

B

`2.466times10^(15)Hz`

C

`4.594times10^(14)Hz`

D

`8.220times10^(14)Hz`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to determine the maximum value of the threshold frequency for a metal that can eject photoelectrons when exposed to ultraviolet radiation from the hydrogen spectrum. Let's break this down step by step. ### Step 1: Understand the Concept of Threshold Frequency The threshold frequency (\( \nu_0 \)) is the minimum frequency of light required to eject photoelectrons from a metal surface. If the frequency of the incident light is greater than this threshold frequency, photoelectrons will be emitted. ### Step 2: Identify the Relevant Series in the Hydrogen Spectrum The ultraviolet region of the hydrogen spectrum primarily includes the Lyman series, which corresponds to electronic transitions from higher energy levels to the first energy level (n=1). The transition that gives the minimum frequency in the Lyman series is from \( n=2 \) to \( n=1 \). ### Step 3: Calculate the Energy Difference The energy levels of the hydrogen atom are given by the formula: \[ E_n = -\frac{13.6 \, \text{eV}}{n^2} \] For the transition from \( n=2 \) to \( n=1 \): \[ E_2 = -\frac{13.6}{2^2} = -\frac{13.6}{4} = -3.4 \, \text{eV} \] \[ E_1 = -\frac{13.6}{1^2} = -13.6 \, \text{eV} \] The energy difference (\( \Delta E \)) for this transition is: \[ \Delta E = E_1 - E_2 = (-13.6) - (-3.4) = -13.6 + 3.4 = -10.2 \, \text{eV} \] ### Step 4: Relate Energy to Frequency The energy of a photon can also be expressed in terms of its frequency using the equation: \[ E = h \nu \] where \( h \) is Planck's constant (\( 6.63 \times 10^{-34} \, \text{Js} \)) and \( \nu \) is the frequency. Therefore, we can set: \[ h \nu = 10.2 \, \text{eV} \] To convert eV to joules, we use the conversion factor \( 1 \, \text{eV} = 1.6 \times 10^{-19} \, \text{J} \): \[ 10.2 \, \text{eV} = 10.2 \times 1.6 \times 10^{-19} \, \text{J} \] ### Step 5: Solve for Frequency Now we can solve for the frequency (\( \nu \)): \[ \nu = \frac{10.2 \times 1.6 \times 10^{-19}}{h} \] Substituting the value of \( h \): \[ \nu = \frac{10.2 \times 1.6 \times 10^{-19}}{6.63 \times 10^{-34}} \] ### Step 6: Calculate the Frequency Calculating the above expression: \[ \nu \approx \frac{1.632 \times 10^{-18}}{6.63 \times 10^{-34}} \approx 2.466 \times 10^{15} \, \text{Hz} \] ### Conclusion The maximum value of the threshold frequency for the metal is approximately: \[ \nu \approx 2.466 \times 10^{15} \, \text{Hz} \]

To solve the problem, we need to determine the maximum value of the threshold frequency for a metal that can eject photoelectrons when exposed to ultraviolet radiation from the hydrogen spectrum. Let's break this down step by step. ### Step 1: Understand the Concept of Threshold Frequency The threshold frequency (\( \nu_0 \)) is the minimum frequency of light required to eject photoelectrons from a metal surface. If the frequency of the incident light is greater than this threshold frequency, photoelectrons will be emitted. ### Step 2: Identify the Relevant Series in the Hydrogen Spectrum The ultraviolet region of the hydrogen spectrum primarily includes the Lyman series, which corresponds to electronic transitions from higher energy levels to the first energy level (n=1). The transition that gives the minimum frequency in the Lyman series is from \( n=2 \) to \( n=1 \). ...
Promotional Banner

Topper's Solved these Questions

  • ATOMIC STRUCTURE

    BITSAT GUIDE|Exercise BITSAT Archives|4 Videos
  • ALTERNATING CURRENT AND EM WAVE

    BITSAT GUIDE|Exercise BITSAT Archives|15 Videos
  • CATHODE RAY, PHOTOELECTRIC EFFECT AND X-RAYS

    BITSAT GUIDE|Exercise BITSAT Archives|6 Videos

Similar Questions

Explore conceptually related problems

Any radiation in the ultra violet region of Hydrogen from a metal . Then the metal is, nearly

Light from balmer series of hydrogen is able to eject photoelectron from a metal what can be the maximum work function of the metal?

It is easier to remove an electron from sodium then from copper. Which metal has higher value of threshold frequency?

The longest wavelength in the ultraviolet region of the hydrogen spectrum is 120nm. What is the smallest wavelength in the infrared region of the hydrogen spectrum ?

The work function of a metal is 3.45 eV. Calculate what should be the maximum wavelength of a photon that can eject photoelectrons from the metal ?

Photoelectric emission is observed from a metallic surface for frequencies v_(1) and v_(2) of the incident light. If the maximum value of kinetic energies of the photoelectrons emitted in the two cases are in the ratio n:1 then the threshold frequency of the metallic surface is

A metal is irradiated with light of frequency 3.2xx10^(16)Hz . The ejected photoelectron has kinetic energy (3)/(4) the of energy of absorbed photon. The threshold frequency orf the metal would be :