Home
Class 12
PHYSICS
Assertion (A) : On increasing the freque...

Assertion (A) : On increasing the frequency of light larger number of photoelectrons are emitted .
Reason (R) : The number of electrons emitted depends on the intensity of incident light.

A

If both A and R are true and R is the correct explanation of A.

B

If both A and R are true but R is not the correct explanation of A.

C

If A is true but R is false

D

If A is false but R is true.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given problem, we need to analyze the assertion and the reason provided in the question. ### Step 1: Analyze the Assertion The assertion states: "On increasing the frequency of light, a larger number of photoelectrons are emitted." - According to the photoelectric effect, the energy of a photon is given by the equation: \[ E_{\text{photon}} = h \nu \] where \( h \) is Planck's constant and \( \nu \) is the frequency of the light. - The number of photoelectrons emitted depends on whether the energy of the photons is sufficient to overcome the work function (\( \phi_0 \)) of the material. - Increasing the frequency increases the energy of each photon, but it does not necessarily increase the number of photons. Thus, while the kinetic energy of emitted electrons may increase, the number of emitted photoelectrons does not increase simply by increasing frequency. **Conclusion for Assertion**: The assertion is **false**. ### Step 2: Analyze the Reason The reason states: "The number of electrons emitted depends on the intensity of incident light." - The intensity of light is related to the number of photons striking the surface per unit time. Higher intensity means more photons are incident on the surface. - If the intensity increases, more photons are available to interact with the electrons in the metal. If each photon has enough energy (greater than the work function), more electrons can be emitted. **Conclusion for Reason**: The reason is **true**. ### Final Conclusion - The assertion is false, and the reason is true. Therefore, the correct interpretation is that the assertion does not support the reason. ### Summary - Assertion (A): False - Reason (R): True
Promotional Banner

Similar Questions

Explore conceptually related problems

As the intensity of incident light increases

The kinetic energy of photoelectrons emitted by a photosensitive surface depends on the internsity of the incident radiation

In the emission of photo-electrons, the number of photo-electrons emitted per unit time depends upon the

Assertion (A) : On increasing the internsity of incident radiation, the photoelectrons eject and then KE increases Reason (R ) : Greater the intensity means greater the energy which in turn means greater the frequency of the radiation.

In photoelectric effect, the number of photoelectrons emitted is proportional to :

In photoelectric effect, the number of photoelectrons emitted is proportional to :

Assertion : Photoelectric current depends on the intensity of incident light. Reason : Number of photoelectrons emitted per second is directly proportional to intensity of incident radiation.

A : On increasing the intensity of light , the number of photoelectrons emitted is more . Also the kinetic energy of each photo increases but the photoelectric current is constant R : Photoelectric current is independent of intensity but increases with increasing frequency incident radiation

When a high frequency electromagnetic radiation is incident on a metallic surface, electrons are emitted from the surface. Energy of emitted photoelectrons depends only on the frequency of incident electromagnetic radiation and the number of emitted electrons depends only on the intensity of incident light. Einstein's protoelectron equation [K_(max)=hv-phi} correctly explains the PE, where upsilon= frequency of incident light and phi= work function. Q. The slope of the graph between stopping potential and frequency is [here h is the Planck's constant and e is the charge of an electron] is

When a high frequency electromagnetic radiation is incident on a metallic surface, electrons are emitted from the surface. Energy of emitted photoelectrons depends only on the frequency of incident electromagnetic radiation and the number of emitted electrons depends only on the intensity of incident light. Einstein's protoelectron equation [K_(max)=hv-phi] correctly ecplains the PE, where upsilon= frequency of incident light and phi= work function. Q. For photoelectric effect in a metal, the graph of the stopping potential V_0 (in volt) versus frequency upsilon (in hertz) of the incident radiation is shown in Fig. The work function of the metal (in eV) is.