Dual nature of radiation and matter practice · Medium

The cathode of a photoelectric cell is changed such that the work function changes from ${W_1}$ to ${W_2}\left( {{W_2} > {W_1}} \right).$ If the current before and after change are ${I_1}$ and ${I_2},$ all other conditions remaining unchanged, then (assuming $hv > {W_2}$)

When subjected to a transverse electric field, cathode rays move

One electron and one proton is accelerated by equal potential. Ratio in their de-Broglie wavelength is

A particle A of mass $‘m’$ and charge $‘q’$ is accelerated by a potential difference of 50 V. another particle $B$ of mass ‘4 m’ and charge $‘q’$ is accelerated by a potential difference of 2500 V. The ratio of de-Broglie wavelengths $\frac{{{\lambda _A}}}{{{\lambda _B}}}$ is close to

If intensity of incident light is increased in PEE then which of the following is true

The de-Broglie wavelength of a proton (charge =1.6$\times {10^{ - 19}}$ C, mass=$1.6 \times {10^{ - 27}}$kg) accelerated through a potential difference of 1kV is

Which of the following statement is not correct?

In a photoelectric effect experiment, the threshold wavelenght of light is 380 nm. If the wavelength of incident light is 260 nm, the maximum kinetic energy of emitted electrons will be
Given, E (in eV) $= \frac{{1237}}{{\lambda (\mathrm{in}\,\,\;\mathrm{nm})}}$

Assertion: The number of photons emitted per second by a point source of light is directly proportional to the power of the source and inversely proportional to the energy of each photon.

Reason: The equation $n=P \lambda / h c$ relates the number of photons emitted per second $(\mathrm{n})$ to the power of the source $(P)$, the wavelength of light emitted $(\lambda)$, and fundamental physical constants ( $\mathrm{h}$ and $\mathrm{c}$ ). This equation shows that increasing the power of the source or decreasing the energy of each photon will result in an increase in the number of photons emitted per second.

A point source of light is used in a photoelectric effect. If the source is removed farther from the emitting metal, the stopping potential :

Which one of the following statement is wrong in the context of X-rays generated from X-ray tube?

In photoelectric effect, the electrons are ejected from metals if the incident light has a certain minimum

Which of the following event, support the quantum nature of light?

The ratio of de-Broglie wavelength of a $\alpha$-particle to that of a proton being subjected to the same magnetic field so that the radii of their path are equal to each other, assuming the field induction $\vec{B}$ present there is perpendicular to the velocity vectors of the $\alpha$-particle and the proton, is

When a piece of metal is illuminated by a monochromatic light of wavelength $\lambda ,\;$ then stopping potential is $3{V_s}.$ When same surface is illuminated by light of wavelength $2\lambda$, then stopping potential becomes ${V_s}.$ The value of threshold wavelength for photoelectric emission will be

The frequency and intensity of a light source are doubled. Consider the following statements

I. Saturation photocurrent remains almost the same.

II. Maximum kinetic energy of the photoelectrons is doubled.

The magnitude of saturation photoelectric current depends upon

The stopping potential in the context of photoelectric effect depends on the following property of incident electromagnetic radiation:

Statement 1: Wave nature of particle is not visible in daily life.

Statement 2: In daily life, mass of particle is very high so their de-Broglie wave length is very small.

The work function of a metal is ${W_0}$ and $\lambda$ is wavelength of incident radiation. There is no emission of photoelectron when

The average energy of the Planck oscillator is

Light of frequency $v$ falls on material of threshold frequency ${v_0}.$ Maximum kinetic energy of emitted electron is proportional to

The momentum of a photon of energy $hv$ will be

When a photon of wavelength 400 nm is incident on a metal surface, the electron emission takes place. The stopping potential to stop electron is 1.5 V. The work function of metal surface is: (given $h c=1240 \mathrm{~eV}-\mathrm{nm})$

Assertion: An electron cannot be observed without changing its momentum by an indeterminate amount.

Reason: Momentum of an electron is $\frac{h}{\lambda}$.

If the momentum of an electron is changed by $\Delta p,$ then the de-Broglie wavelength associated with it changes by 0.50%. The initial momentum of the electron will be

In Millikans oil drop experiment, a charged drop of mass $1.8 \times {10^{ - 14}}kg$ is stationary between its plates. The distance between its plates is $0.90\;cm$ and potential difference is $2.0\;kilo\;volts.$ The number of electrons on the drop is

The increase in the energy of an electron for changing its de-Broglie wavelength from $1\,\mathop \mathrm{A}\limits^\mathrm{o} \mathrm{ }\,\,\mathrm{to}\,\,\mathrm{ }0.5\,\mathop \mathrm{A}\limits^\mathrm{o} \,$ will be-

A proton moving with one tenth of velocity of light has a certain de Broglie wavelength of $\lambda$. An alpha particle having certain kinetic energy has the same de-Brogle wavelength $\lambda$. The ratio of kinetic energy of proton and that of alpha particle is

According to photon theory of light which of the following physical quantities associated with a photon do not/does not change as it collides with an electron in vacuum