Particle Nature of Light: The Photon

If the energy of a photon is given as, $\text{E}=3.03\times {10}^{-19} \mathrm{J}$, then, the wavelength $\mathrm{(\lambda )}$ of the photon is

Sun gives light at the rate of $1400 {\mathrm{Wm}}^{-2}$ of the area perpendicular to the direction of the light. Assume ${\lambda }_{\left(sunlight\right)}=6000 \stackrel{°}{\mathrm{A}}$. Calculate the number of protons/sec arriving at $1 {\mathrm{m}}^2$ area at that part of the earth.

Explain about dual nature of light.

Which of the is n the property of photon?

A photon of blue colour light wavelength ${\lambda }_0$ enters into a medium of refractive index $\mu =\frac{4}{3}$, then change in energy of photon is $\frac{\alpha hc}{3{\lambda }_0}$. Find the value of $\alpha$.

Rocket$\text{'}A\text{'}$ travels towards the right and rocket $\text{'}B\text{'}$ travels to the left, with velocities$0.8c$and$0.6c$, respectively. relative to earth. what is the velocity of rocket $\text{'}A\text{'}$ measured from rocket $\text{'}B\text{'}$ ?

A source of light of power$P$  is shown in figure. Find the force on the block placed in the path of the light rays. The surface of body on which the light beam is incident is having a reflection coefficient $a_r$= $0.7$ and absorption coefficient $a_a=0.3$

The equation $E=pc$ is valid

 

Calculate (a) the energy in Joule for $\lambda = 4000 \stackrel{\circ }{\mathrm{A}}$, (b) the energy in eV for $\nu = 5\times {10}^{-3} \mathrm{Hz}$.

The Ground state energy of hydrogen atom is $0.6\mathrm{eV}$. If the electrons make a transition from $0.85 \mathrm{eV}$ to $3.4 \mathrm{eV}$. Calculate the wavelength of spectral wavelength emitted.
 

All photons present in a light beam of a particular frequency have: 

What is the numerical value of plank constant?

If the maximum kinetic energy of the photoelectron is $12$eV. Then, the maximum stopping potential will be-____.

Which of the following statements is NOT true?

It has been experimentally demonstrated that

The energy of a photon having wavelength $700\mathrm{nm}$ is: $\left(hc=1242 \mathrm{eV} \mathrm{nm}\right)$

If a Light Source is moving along the direction of Principle axis towards mirror which is at a distance $40 \mathrm{cm}$ initially with speed of $2 \mathrm{mm} {\mathrm{s}}^{-1}$. The source ejects nearly ${10}^{20}$ photons per second each of wavelength $99.2 \stackrel{\circ }{\mathrm{A}}$ are striking mirror. If Ice of mass $10 \mathrm{g}$ is kept right below the initial position of Source as given in the figure. Find the amount of water formed after $1 \mathrm{s}$. [Reflective power of Mirror$=0.5$. Latent heat of fusion Ice $=80 \mathrm{cal} {\mathrm{g}}^{-1}$]

[Round off to nearest Integer]

Three monochromatic sources having wavelengths $12.42 \mathrm{nm}, 6.21 \mathrm{nm}$ and $24.84 \mathrm{nm}$ are placed close to each other in front of a converging lens such that equal powers from the three equal to $1 \mathrm{m} \mathrm{W}$ each fall on a converging lens and then on a small spherical conductor of radius $r=1 \mathrm{mm}$ and work function $62.1\mathrm{eV}$ (Assume $50\%$ efficiency of emission and no change in effective value of work function due to photoelectric emission and potential rise) (Use $hc=1242 \mathrm{eV}-\mathrm{nm}$) (All electrons emitted by the sphere are immediately removed by some non-electrical mechanism). At $t=8 \sec$ switch $S$ is closed so that the sphere gets connected to the earth via a resistor of value $6.75 \Omega$. Find the current flowing just after the switch is closed.

Explain the interaction of radiation with matter.

The remote control of a TV emits infra-red light of wavelength $900\mathrm{nm}$. The TV detector is made of a semiconductor whose band gap is $x \mathrm{eV}$. The detector is shielded by a semiconductor optical filter whose band gap is $y \mathrm{eV}$. From the four options below, select the best option for the TV to function.