UV light of is incident on a photosensitive metal surface having a work function of . The maximum kinetic energy of the ejected photoelectrons will be:
- A
- B
- C
- D
UV light of is incident on a photosensitive metal surface having a work function of . The maximum kinetic energy of the ejected photoelectrons will be:
Correct answer:B
Standard Method
Given: Energy of incident UV light is and work function of the metal is .
Find: The maximum kinetic energy of the ejected photoelectrons.
Using Einstein's photoelectric equation:
Substituting the given values:
Therefore, the maximum kinetic energy of the ejected photoelectrons is . The correct option is B.
Direct Energy Difference
Given: Incident photon energy is and work function is .
Find: Maximum kinetic energy.
In the photoelectric effect, the emitted electron gets the leftover energy after overcoming the work function. So subtract the work function from the incident photon energy:
Therefore, the correct option is B.
Using the incident photon energy itself as the kinetic energy is incorrect because part of that energy is first used to overcome the work function. Always subtract from .
Taking the work function as the answer is incorrect because is the minimum energy needed for emission, not the kinetic energy of the emitted electron.
Adding and is incorrect because the photoelectric equation is , not a sum. The work function is an energy cost, not an extra gain.
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