COMEDK · Physics · 27. Dual Nature of Matter
Ultraviolet light of wavelength \(99 \text{ nm}\) falls on a metal plate of work function \(1.0 \text{ eV}\). If the mass of the electron is \(9.1 \times 10^{-31} \text{ kg}\), the de Broglie wavelength of the fastest photoelectron emitted is
- A \(0.63 \mathrm{~nm}\)
- B \(0.66 \mathrm{nm}\)
- C \(0.33 \mathrm{~nm}\)
- D \(0.36 \mathrm{~mm}\)
Answer & Solution
Correct Answer
(D) \(0.36 \mathrm{~mm}\)
Step-by-step Solution
Detailed explanation
\(E = \dfrac{hc}{\lambda} = \dfrac{1242\,\text{eV·nm}}{99\,\text{nm}} \approx 12.54\,\text{eV}\) \(K_{max} = E - \Phi = 12.54 - 1.0 = 11.54\,\text{eV}\) Using the de Broglie wavelength formula for electrons:…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- The layer in the Earth's atmosphere which reflects radio waves from the Earth, thus helping radio communication isCOMEDK 2012 Easy
- \(O\) is the centre of an equilateral triangle \(A B C\). \(F_1, F_2\) and \(F_3\) are three forces acting along the sides \(A B, B C\) and \(A C\) as shown in figure.

What should be the magnitude of \(F_3\), so that the total torque about \(O\) is zero?COMEDK 2024 Easy - Three identical conducting balls A, B and C, each of mass m, are thrown upward at an angle \(\Theta\) to the horizontal with an initial speed \(v\) in a region of space that has a uniform electric field \(E\) downward along with the gravitational field \(g\). A is positively charged, B is uncharged and C is negatively charged. Rank the ranges R of these three balls in increasing order.COMEDK 2025 Medium
- The height vertically above the earth's surface at which the acceleration due to gravity becomes \(1 \%\) of its value at the surface isCOMEDK 2023 Medium
- The intensity of magnetic field due to an isolated pole of strength \(m_{p}\) at a point distant \(r\) from it will beCOMEDK 2020 Medium
- A person has a normal near point \(25 \mathrm{~cm}\). What is the magnifying power of the simple microscope he used, if the focal length of the convex lens used is \(10 \mathrm{~cm}\) and the final image is formed at the least distance of distinct vision?COMEDK 2023 Easy
More PYQs from COMEDK
- If the distance ' \(S\) metres traversed by a particle in \(t\) seconds is given by \(S=t^{3}-3 t^{2}\), then the velocity of the particle when the acceleration is zero, in \(\mathrm{m} / \mathrm{sec}\) isCOMEDK 2013 Easy
- The radius of the current carrying circular coil is doubled keeping the current passing through it the same. Then the ratio of the magnetic field produced at the centre of the coil before the doubling of the radius to the magnetic field after doubling of the radius.COMEDK 2023 Easy
- A gas bubble of volume \(2 \mathrm{~cm}^3\) rises from the bottom of a pond of depth 10 m at \(17^0 \mathrm{C}\). What will be the volume of the bubble when it reaches the surface of the pond? Atmospheric temperature is \(27^{\circ} \mathrm{C}\) and the pressure at the bottom of the pond is double that of the pressure at the surface.COMEDK 2025 Medium
- In a kabaddi league, two matches are being played between Jaipur and Delhi. It is assumed that the outcomes of the two games are independent. The probability of Jaipur winning, drawing and losing the game against Delhi are \(\dfrac{1}{2}, \dfrac{3}{10}\) and \(\dfrac{1}{5}\) respectively. Each team gets 5 points for win, 3 points for draw and 0 points for loss in a game. After two games, find the probability that Jaipur has more points than Delhi.COMEDK 2025 Medium
- Which of the following gas is responsible for acid rain?COMEDK 2022 Easy
- Choose the incorrect statement.COMEDK 2026 Medium