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The photoelectric threshold wavelength o...

The photoelectric threshold wavelength of silver is `3250 xx 10^(-10) m`. The velocity of the electron ejected from a silver surface by ultraviolet light of wavelength `2536 xx 10^(-10) m` is
`(Given h = 4.14 xx 10^(6) ms^(-1) eVs` and `c = 3 xx 10^(8) ms^(-1))`

A

`=6xx10^(5)ms^(-1)`

B

`=0.6xx10^(6)ms^(-1)`

C

`=61xx10^(3)ms^(-1)`

D

`=0.3xx10^(6)ms^(-1)`

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The correct Answer is:
To find the velocity of the electron ejected from a silver surface by ultraviolet light, we will use the photoelectric effect principles and the relevant equations. ### Step-by-Step Solution: 1. **Identify Given Values:** - Threshold wavelength of silver, \( \lambda_0 = 3250 \times 10^{-10} \, \text{m} \) - Wavelength of incident light, \( \lambda = 2536 \times 10^{-10} \, \text{m} \) - Planck's constant, \( h = 4.14 \times 10^{-6} \, \text{ms}^{-1} \, \text{eVs} \) - Speed of light, \( c = 3 \times 10^{8} \, \text{ms}^{-1} \) - Mass of electron, \( m = 9.1 \times 10^{-31} \, \text{kg} \) 2. **Calculate the Energy of the Incident Photon:** \[ E = \frac{hc}{\lambda} \] Substitute the values: \[ E = \frac{(4.14 \times 10^{-6} \, \text{ms}^{-1} \, \text{eVs})(3 \times 10^{8} \, \text{ms}^{-1})}{2536 \times 10^{-10} \, \text{m}} \] 3. **Calculate the Energy of the Threshold Photon:** \[ E_0 = \frac{hc}{\lambda_0} \] Substitute the values: \[ E_0 = \frac{(4.14 \times 10^{-6} \, \text{ms}^{-1} \, \text{eVs})(3 \times 10^{8} \, \text{ms}^{-1})}{3250 \times 10^{-10} \, \text{m}} \] 4. **Calculate the Kinetic Energy of the Ejected Electron:** The kinetic energy \( KE \) of the ejected electron is given by: \[ KE = E - E_0 \] 5. **Relate Kinetic Energy to Velocity:** The kinetic energy of the electron can also be expressed as: \[ KE = \frac{1}{2} mv^2 \] Setting the two expressions for kinetic energy equal gives: \[ \frac{1}{2} mv^2 = E - E_0 \] 6. **Solve for Velocity \( v \):** Rearranging gives: \[ v = \sqrt{\frac{2(E - E_0)}{m}} \] 7. **Substitute and Calculate:** Substitute the calculated values of \( E \) and \( E_0 \) into the equation to find \( v \). ### Final Calculation: After performing the calculations, we find: \[ v \approx 0.6 \times 10^{6} \, \text{m/s} \] ### Conclusion: The velocity of the ejected electron is approximately \( 0.6 \times 10^{6} \, \text{m/s} \).

To find the velocity of the electron ejected from a silver surface by ultraviolet light, we will use the photoelectric effect principles and the relevant equations. ### Step-by-Step Solution: 1. **Identify Given Values:** - Threshold wavelength of silver, \( \lambda_0 = 3250 \times 10^{-10} \, \text{m} \) - Wavelength of incident light, \( \lambda = 2536 \times 10^{-10} \, \text{m} \) - Planck's constant, \( h = 4.14 \times 10^{-6} \, \text{ms}^{-1} \, \text{eVs} \) ...
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