Saved Bookmarks
| 1. |
The work function of a photosensitive material is4.0 eV. The longest wavelength of light that cancause photon emission from the substance is(approximately)[NEET - 2019 (Odisha)](1) 310 nm(2) 3100 nm(3) 966 nm(4) 31 nm |
Answer» answer : option (1) 310 nmwork function of a photosensitive material is 4 eV. we know, 1eV = 1.6 × 10^-19 J so, work function = 4 × 1.6 × 10^-19 J LET's FIND threshold wavelength, work function, Φ = hc/λ ⇒4 × 1.6 × 10^-19 J = 6.625 × 10^-34 × 3 × 10^8/λ ⇒λ = (6.625 × 3 × 10^-26)/(6.4 × 10^-19) ⇒ λ = 3.1 × 10^-7 m = 310 nm for emission of photons from metal surface, wavelength must be less than or equal to threshold wavelength. hence, maximum wavelength = threshold wavelength = 310 nm also read similar questions : The work function of sodium metal is 2.28 eV. The APPROXIMATE value of longest wavelength (in angstrom) which can result... The ground state energy of hydrogen atom is -13.6eV. The photon emitted during the transition of electron from n = 2 to ... |
|