Question

In photoelectric effect work function of any metal is 2.5 eV. The most energetic emitted electrons are stopped by the potential of -1.5 volt then
1) energy of incident photons is 4eV
2) energy of incident photons is leV
3) photoelectric current increases when we use photons of high frequency
4) energy of incident photons is 3eV​

Answer 1

Answer:

4 eV

Explanation:

If the electrons are stopped by a potential of -1.5 V  then its Kinetic Energy would have been 1.5 V.

We know that -

$K.E_{max}=hv - hv_0$

⇒$1.5 = hv-2.5$

⇒$hv = 4eV = Ans$

Answer 2

Answer:

4 eV

Explanation:

If the electrons are stopped by a potential of -1.5 V  then its Kinetic Energy would have been 1.5 V.

We know that -  

K.E_{max}=hv - hv_0

⇒1.5 = hv-2.5

⇒hv = 4eV = Ans