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A point source of light is taken away from the experimental setup of photoelectric effect. For this situation, mark out the correct statement(s).

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Important Questions on Dual Nature of Matter and Radiation

EASY

Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

6.4 \times 10^{- 19}

joule is approximately

EASY

Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

The surface of a metal is illuminated with a light of wavelength

400 nm

. The kinetic energy of the ejected photoelectrons was found to be

1.68 eV

. The work function of the metal is

(h c = 1240 eV nm)

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Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

What is photoelectric effect?

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Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

The radiation corresponding to

3 \to 2

transition of a hydrogen atom falls on a gold surface to generate photoelectrons. These electrons are passed through a magnetic field of

5 \times 10^{- 4} T

. Assume that the radius of the largest circular path followed by these electrons is

7 mm

, the work function of the metal is:
(Mass of electron

= 9.1 \times 10^{- 31} kg

)

HARD

Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

When photon of energy

4.0 e V

strikes the surface of a metal

A,

the ejected photoelectrons have maximum kinetic energy

T_{A} e V

and de-Broglie wavelength

λ_{A} .

The maximum kinetic energy of photoelectrons liberated from another metal

B

by photon of energy

4.50 e V

T_{B} = (T_{A} - 1.5) e V .

If the de-Broglie wavelength of these photoelectrons

λ_{B} = 2 λ_{A},

then the work function of metal

B

is:

EASY

Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

What is work function?

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Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

A beam of photons with an energy of

10.5 eV

strike a metal plate. The photoelectrons are emitted with maximum velocity of

1.6 \times 10^{6} m s^{- 1}

. The work function of the metal is
(Assume mass of electron

= 9 \times 10^{- 31} kg

and Charge of electron

= 1.6 \times 10^{- 19} C

)

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Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

If the light of wavelength $412.5 nm$ is incident on each of the metals given below, which ones will show photoelectric emission and why?

Metal	Work Function(eV)
Na	1.92 eV
K	2.15 eV
Ca	3.20 eV
Mo	4.17 eV

HARD

Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

Radiation, with wavelength

6561 Å

falls on a metal surface to produce photoelectrons. The electrons are made to enter a uniform magnetic field of

3 \times 10^{- 4} T

. If the radius of the largest circular path followed by the electrons is

10 m m

, the work function of the metal is close to:

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Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

Given figure shows few data points in a photo-electric effect experiment for a certain metal. The minimum energy for ejection of electrons from its surface is: (Planck's constant $h = 6.62 \times 10^{- 34} J.s$ )

Question Image

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Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

Which of these statements is true regarding photoelectric emission?

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Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

The continuous part of

X

-ray spectrum is a result of the

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Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

The work function of a metal is $1.5 eV .$ Light of wavelength $2500 \overset{o}{A}$ is incident on this metal. Maximum velocity of photoelectrons is

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Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

The stopping potential for electrons emitted from a photosensitive surface illuminated by light of wavelength

491 nm

0.710 V .

When the incident wavelength is changed to a new value, the stopping potential is

1.43 V .

The new wavelength is :

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Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

The photoelectric effect proves that

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Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

What is the photoelectric effect? Define Photoelectric work function.

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Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

What is photoelectric effect? Define Stopping potential.

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Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

Light of frequency

1.5

times the threshold frequency is incident on a photosensitive material. What will be the photoelectric current if the frequency is halved and intensity is doubled?

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Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

A metal surface is illuminated by light of two different wavelengths 248 nm and 310 nm. The maximum speeds of the photoelectrons corresponding to these wavelengths are u₁ and u₂, respectively. If the ratio

u_{1} : u_{2} = 2 : 1

and

h c = 1240 eV nm

, the work function of the metal is nearly

EASY

Physics>Modern Physics>Dual Nature of Matter and Radiation>Photoelectric Effect

A photoelectric surface is illuminated successively by monochromatic light of wavelength

λ

and

\frac{λ}{2}

. If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case, the work function of the surface of the material is:
(

h

= Planck's constant,

c

= speed of light)

A point source of light is taken away from the experimental setup of photoelectric effect. For this situation, mark out the correct statement(s).

Important Questions on Dual Nature of Matter and Radiation

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