Q.
The work function of some metals is listed below. The
number of metals which will show photoelectric effect when
light of wavelength falls on the metal is
Metal
Li
Na
K
Mg
Cu
Ag
Fe
pt
W
(eV)
2.4
2.3
2.2
3.7
4.8
4.3
4.7
6.3
4.75
Metal | Li | Na | K | Mg | Cu | Ag | Fe | pt | W |
(eV) | 2.4 | 2.3 | 2.2 | 3.7 | 4.8 | 4.3 | 4.7 | 6.3 | 4.75 |
Answer: 4
Solution: