What is the work function of the metal if the light of wavelength 4000 Å generates photoelectrons of velocity 6 × 105 ms−1 form it?
(Mass of electron = 9 × 10−31 kg Velocity of light = 3 × 108 ms−1 Planck's constant = 6.626 × 10−34 Js Charge of electron = 1.6 × 10−19 JeV−1)
a.
0.9 eV
b.
4.0 eV
c.
2.1 eV
d.
3.1 eV
a.
0.9 eV
b.
4.0 eV
c.
2.1 eV
d.
3.1 eV
Question ID - 52362 | SaraNextGen Top Answer What is the work function of the metal if the light of wavelength 4000 Å generates photoelectrons of velocity 6 × 105 ms−1 form it?
(Mass of electron = 9 × 10−31 kg Velocity of light = 3 × 108 ms−1 Planck's constant = 6.626 × 10−34 Js Charge of electron = 1.6 × 10−19 JeV−1)
a.
0.9 eV
b.
4.0 eV
c.
2.1 eV
d.
3.1 eV
What is the work function of the metal if the light of wavelength 4000 Å generates photoelectrons of velocity 6 × 105 ms−1 form it?
(Mass of electron = 9 × 10−31 kg Velocity of light = 3 × 108 ms−1 Planck's constant = 6.626 × 10−34 Js Charge of electron = 1.6 × 10−19 JeV−1)
|
a. |
0.9 eV |
b. |
4.0 eV |
|
c. |
2.1 eV |
d. |
3.1 eV |
1 Answer
127 votes
Answer Key / Explanation : (c) -
hv = 
+hv0
mv2 = hc
hv = 
+ 
mv2
= 
9 
10−31 
(6 
105)2
= 3.35 
10−19J
⇒ 
2.1 eV
127 votes
Answer Link
127