iCON Education - Dual Nature of Radiation AP-EAPCET Test

When photons of energy $8 \times 10^{-19} \mathrm{~J}$ incident on a photosensitive material, the de-Broglie wavelength of the photoelectrons emitted with maximum kinetic energy is $10 $ Å. The work function of the photosensitive material is nearly

The minimum wavelength of X-rays produced by 20 kV electrons is nearly

$0.62 \mathop {\rm{A}}\limits^{\rm{o}}$

$1.8 \mathop {\rm{A}}\limits^{\rm{o}}$

$3.2 \mathop {\rm{A}}\limits^{\rm{o}}$

$6.5 \mathop {\rm{A}}\limits^{\rm{o}}$

The de-Broglie wavelength associated with an electron accelerated through a potential difference of $\frac{200}{3} \mathrm{~V}$ is nearly

$25 \mathop {\rm{A}}\limits^{\rm{o}}$

$2.5 \mathop {\rm{A}}\limits^{\rm{o}}$

$15 \mathop {\rm{A}}\limits^{\rm{o}}$

$1.5 \mathop {\rm{A}}\limits^{\rm{o}}$

The ratio of de-Broglie wavelengths associated with thermal neutrons at temperatures $127^{\circ} \mathrm{C}$ and $352^{\circ} \mathrm{C}$ is

A laser produces a beam of light of frequency $5 \times 10^{14}$ Hz with an output power of 33 mW . The average number of photons emitted by the laser per second is (Planck's constant $=6.6 \times 10^{-34} \mathrm{Js}$ )

If the de-Broglie wavelength of an electron is 2 nm , then its kinetic energy is nearly (Planck's constant $=6.6 \times 10^{-34} \mathrm{Js}$ and mass of electron $=9 \times 10^{-31} \mathrm{~kg}$ )

If a proton and an alpha particle are accelerated through the same potential difference, then the ratio of their de-Broglie wavelengths is

If the threshold wavelength of light for photoelectric emission to take place from a metal surface is $6250 \mathop {\rm{A}}\limits^{\rm{o}}$, then the work function of the metal is (Planck's constant $=6.6 \times 10^{-34} \mathrm{Js}$ )

A camera is fabricated using a semiconducting material having a band gap of 3 eV . The wavelength of light if can detect is nearly

If the linear momentum of a proton is changed by $p_0$ then the de-Broglie wavelength associated with the proton changes by $0.25 \%$. Then the initial linear momentum of the proton is

If an electron in the excited state falls to ground state, a photon of energy 5 eV is emitted, then the wavelength of the photon is nearly

A photon incident on a metal of work function 2 eV produced photoelectron of maximum kinetic energy of 2 eV . The wavelength associated with the photon is

$6200 \mathop {\rm{A}}\limits^{\rm{o}}$

$3100 \mathop {\rm{A}}\limits^{\rm{o}}$

$9300 \mathop {\rm{A}}\limits^{\rm{o}}$

$2000 \mathop {\rm{A}}\limits^{\rm{o}}$

Light of wavelength $4000\mathop {\rm{A}}\limits^{\rm{o}}$ is incident on a sodium surface for which the threshold wavelength of photoelectrons is $5420 \mathop {\rm{A}}\limits^{\rm{o}}$. The work function of sodium is

The surface of a metal is first illuminated with a light of wavelength 300 nm and later illuminated by another light of wavelength 500 nm . It is observed that the ratio of maximum velocities of photoelectrons in two cases is 3 . The work function of metal value is close to

The maximum wavelength of light which causes photoelectric emission from photosensitive metal surface is $\lambda_0$. Two light beams of wavelengths $\frac{\lambda_0}{3}$ and $\frac{\lambda_0}{9}$ incident on the metal surface. The ratio of the maximum velocities of the emitted photoelectrons is

A blue lamp emits light of mean wavelength $4500$ Å. The lamp is rated at 150 W and $8 \%$ efficiency. Then, the number of photons are emitted by the lamp per second

$27.17 \times 10^{18}$

$17.17 \times 10^{18}$

$27.17 \times 10^{15}$

If the kinetic energy of a particle in motion is decreased by $36 \%$, the increase in de-Broglie wavelength of the particle is

An electron of mass $m$ with initial velocity $\mathbf{v}=v_0 \hat{\mathbf{i}}\left(v_0>0\right)$ enters in an electric field $\mathbf{E}=-E_0 \hat{\mathbf{i}}$ ( $E_0$ is constant $>0$ ) at $t=0$. If $\lambda$ is its de-Broglie wavelength initially, then the de-Broglie wavelength after time $t$ is

$\frac{\lambda}{1+\frac{e E_d}{m v_0}}$

$\frac{\lambda}{\left(1-\frac{e E_d}{m v_0}\right)^2}$

$\left(1+\frac{e E_\alpha}{m v_0}\right) \lambda$

$\left(1+\frac{e E_d}{m v_0}\right)^2 \lambda$

The longest wavelength of light that can initiate photo electric effect in the metal of work function 9 eV is

$1.37 \times 10^{-7} \mathrm{~m}$

$1.5 \times 10^{-7} \mathrm{~m}$

$3.7 \times 10^{-7} \mathrm{~m}$

$4 \times 10^{-7} \mathrm{~m}$

Energy required to remove an electron from aluminium surface is 4.2 eV . If light of wavelength $2000 \mathring{A}$ falls on the surface, the velocity of the fastest ejected electron the surface will be

$84 \times 10^5 \mathrm{~ms}^{-1}$

$7.4 \times 10^6 \mathrm{~ms}^{-1}$

$64 \times 10^5 \mathrm{~ms}^{-1}$

$84 \times 10^6 \mathrm{~ms}^{-1}$

The following statement is correct in the case of photoelectric effect

For a given frequency of incident radiation, the stopping potential varies linearly with its intensity.

For a given frequency of incident radiation, the photocurrent is independent of its intensity.

For a given frequency of a incident radiation, the maximum kinetic energy of the photoelectrons is independent of its intensity.

For a frequency lower than cutoff frequency, photoelectric emissions can occur if intensity of incident light is increased slightly.

In a photoelectric experiment light of wavelength 800 nm produces photoelectrons with the smallest de-Broglie wavelength of 1 nm . Light of 400 nm produces photoelectrons with smallest de-Broglie wavelength of 0.5 nm. Then the work function of the metal used in the experiment is nearly.

The metal which has the highest work function in the following is

If a photocell is illuminated with a radiation of 1240 $\mathop A\limits^o $, the stopping potential is found to be 8V. Then, the work-function of the emitter and the threshold wavelength are

2 eV, 2000 $\mathop A\limits^o $

2 eV, 6200 $\mathop A\limits^o $

2 eV, 2480 $\mathop A\limits^o $

3 eV, 6200 $\mathop A\limits^o $

The graph between the maximum speed $(v_{max})$ of a photoelectron and frequency $(\nu)$ of the incident radiation, in photoelectric effect is correctly represented by

The de-Broglie wavelength associated with a proton under the influence of an electric potential of 100 V is

1.227 $\mathop A\limits^o $

12.27 $\mathop A\limits^o $

1.146 $\times$ 10$^{-21}$ m

Radiation of wavelength $300 \mathrm{~nm}$ and intensity $100 \mathrm{~W}-\mathrm{m}^{-2}$ falls on the surface of a photosensitive material. If $2 \%$ of the incident photons produce photoelectron, the number of photoelectrons emitted from an area of $2 \mathrm{~cm}^2$ of the surface is nearly

$6.04 \times 10^{14}$

$1.5 \times 10^{12}$

$60.4 \times 10^{15}$