Which of the following figures represents the variation of the particle momentum and the associated de-Broglie wavelength?
1. | 2. | ||
3. | 4. |
Light with a wavelength of \(500\) nm is incident on a metal with a work function of \(2.28\) eV. The de Broglie wavelength of the emitted electron will be:
1. \( <2.8 \times 10^{-10}~\text{m} \)
2. \( <2.8 \times 10^{-9}~\text{m} \)
3. \( \geq 2.8 \times 10^{-9}~\text{m} \)
4. \( <2.8 \times 10^{-12}~\text{m} \)
Light with an energy flux of \(25\times 10^{4}~\text{Wm}^{-2}\) falls on a perfectly reflecting surface at normal incidence. If the surface area is \(15~\text{cm}^2\), then the average force exerted on the surface is:
1. \(1.25\times 10^{-6}~\text{N}\)
2. \(2.5\times 10^{-6}~\text{N}\)
3. \(1.2\times 10^{-6}~\text{N}\)
4. \(3.0\times 10^{-6}~\text{N}\)
What will be the percentage change in the de-Broglie wavelength of the particle if the kinetic energy of the particle is increased to \(16\) times its previous value?
1. \(25\)
2. \(75\)
3. \(60\)
4. \(50\)
A 200W sodium street lamp emits yellow light of wavelength Assuming it to be 25% efficient in converting electrical energy to light, the number of photons of yellow light it emits per second is
(1)
(2)
(3)
(4)
Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be 3.57 V.The threshold frequency of the material is:
(1)
(2)
(3)
(4)
1. | \(1~\mathring{A}\) | 2. | \(0.1~\mathring{A}\) |
3. | \(10~\mathring{A}\) | 4. | \(0.01~\mathring{A}\) |