NEET Physics Dual Nature of Radiation and Matter : Multiple Choice Previous Years Questions MCQs 1

TL;DR

This video discusses the concepts of wavelength, stopping potential, and work function in relation to the dual nature of radiation and matter.

Transcript

hello friends this video on neat dual nature of radiation and matter is brought to you by example.com no more fear from exam so now it is time for mcqs let us try to solve different types of mcqs and see how do we need to handle them question number one when a metallic surface is illuminated with radiation of wavelength lambda the stopping potentia... Read More

Key Insights

• 💦 The photoelectric equation links stopping potential, wavelength, and work function.
• ✋ The threshold wavelength can be calculated using the photoelectric equation and the given stopping potential.
• 💦 The work function of a metal can be calculated by considering the kinetic energy of photoelectrons moving in a circular path in a magnetic field.

Questions & Answers

Q: How can we calculate the threshold wavelength for a metallic surface based on stopping potential and wavelength?

By applying the photoelectric equation and equating the stopping potential with the maximum kinetic energy, we can derive the threshold wavelength as three times the given wavelength.

Q: How can we determine the work function of a metal based on the kinetic energy of photoelectrons moving in a magnetic field?

By equating the centripetal force and the force due to the magnetic field, we can derive the velocity and, subsequently, the maximum kinetic energy. Plugging this value into the photoelectric equation, we can calculate the work function.

Q: If two identical metal plates are exposed to light of different wavelengths, how can we compare the maximum kinetic energy of the photoelectrons emitted?

By using the photoelectric equation and substituting the wavelengths and work function, we can express the kinetic energy of one plate in terms of the kinetic energy of the other. This shows that the kinetic energy of plate A is less than half the kinetic energy of plate B.

Summary & Key Takeaways

• The first question examines the relationship between stopping potential and wavelength to calculate the threshold wavelength for a metallic surface.

• The second question explores how the work function can be derived using the kinetic energy of photoelectrons moving in a circular path in a magnetic field.

• The third question compares the maximum kinetic energy of photoelectrons on two identical metal plates and establishes a relation between the two.