The surface of certain metal is first illuminated with light of wavelength $λ_{1} = 350 n m$ and then, by a light of wavelength $λ_{2} = 540 n m .$ It is found that the maximum speed of the photoelectrons in the two cases differ by a factor of $2$ . The work function of the metal (in $e V$ ) is close to

(Energy of photon $= \frac{1240}{λ (i n n m)} e V$ )

Question

The surface of certain metal is first illuminated with light of wavelength

λ_{1} = 350 n m

and then, by a light of wavelength

λ_{2} = 540 n m .

It is found that the maximum speed of the photoelectrons in the two cases differ by a factor of

2

. The work function of the metal (in

e V

) is close to

(Energy of photon

= \frac{1240}{λ (i n n m)} e V

)

Aicharya · Accepted Answer

&#955; 1 = 350 &#160;n m , &#8201;&#8201; &#955; 2 = 540 &#8201; n m , &#160; &#160; V 1 V 2 = 2 &#8658; V 1 = 2 V &#160; a n d &#160; V 2 = V h c &#955; 1 = &#981; + 1 2 m 2 V 2 h c &#955; 2 = &#981; + 1 2 m V 2 h c &#955; 1 - 4 h c &#955; 2 = &#981; - 4 &#981; h c 4 540 - 1 340 = 3 &#981; &#981; = 1.8 &#160; e V

The surface of certain metal is first illuminated with light of wavelength λ 1 = 350 n m and then, by a…

Solution