Dual Nature Of Radiation And Matter | Physics JEE previous year questions with Solutions

Q 1 :

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): Number of photons increases with increase in frequency of light.

Reason (R): Maximum kinetic energy of emitted electrons increases with the frequency of incident radiation.

In the light of the above statements, choose the most appropriate answer from the options given below: [2024]

Both A and R are correct and R is not the correct explanation of A.
Both A and R are correct and R is the correct explanation of A.
A is correct, but R is not correct.
A is not correct, but R is correct.

1

2

3

4

(4)

Intensity of light $I = \frac{n h ν}{A}$ , Here $v$ is no. of photons per unit time.

$n = \frac{I A}{h ν}$ , so on increasing frequency $v,$ $n$ decreases taking intensity constant. Number of photons remains unchanged with increase in frequency.

$k_{\max} = h ν - ϕ$

So on increasing $v$ , kinetic energy increases.

Q 2 :

Which of the following statement is not true about stopping potential $(V_{0})$ ? [2024]

It depends upon frequency of the incident light.
It increases with increase in intensity of the incident light.
It is 1/e times the maximum kinetic energy of electrons emitted.
It depends on the nature of emitter material.

1

2

3

4

(2)

$K E_{m a x} = h ν - ϕ_{0} = e V$

Q 3 :

In photoelectric experiment energy of 2.48 eV irradiates a photo sensitive material. The stopping potential was measured to be 0.5 V. Work function of the photo sensitive material is : [2024]

2.48 eV
0.5 eV
1.98 eV
1.68 eV

1

2

3

4

(3)

$e V_{s} = h ν - ϕ$

$0.5 e V = 2.48 e V - ϕ$

Work function, $ϕ = (2.48 - 0.5) e V = 1.98 e V$

Q 4 :

When UV light of wavelength 300 nm is incident on the metal surface having work function 2.13 eV, electron emission takes place. The stopping potential is [2024]

4.1 V
2 V
4 V
1.5 V

1

2

3

4

(2)

Energy incident on the metal surface,

$E = \frac{h c}{λ} = \frac{1240}{300} e V \Rightarrow E = 4.13 e V$

Work function, $ϕ = 2.13 e V$

$E = ϕ + e V_{s} = 4.13 e V - 2.13 e V = 2 e V_{s} \Rightarrow V_{s} = 2 V$

Q 5 :

UV light of 4.13 eV is incident on a photosensitive metal surface having work function 3.13 eV. The maximum kinetic energy of ejected photoelectrons will be [2024]

4.13 eV
1 eV
3.13 eV
7.26 eV

1

2

3

4

(2)

As we know that

${(K . E .)}_{m a x} = E_{p h o t o n} -$ work function $= h ν - ϕ$

${(K . E .)}_{m a x} = 4.13 e V - 3.13 e V$

Max $K . E . = 1 e V$

Q 6 :

A convex lens of focal length 40 cm forms an image of an extended source of light on a photoelectric cell. A current $I$ is produced. The lens is replaced by another convex lens having the same diameter but focal length 20 cm. The photoelectric current now is [2024]

$\frac{I}{2}$
$4 I$
$2 I$
$I$

1

2

3

4

(4)

As amount of energy incident on cell is same so current will remain same.

Q 7 :

The threshold frequency of a metal with work function 6.63eV is [2024]

$16 \times 10^{15} H z$
$16 \times 10^{12} H z$
$1.6 \times 10^{12} H z$
$1.6 \times 10^{15} H z$

1

2

3

4

(4)

$ϕ_{0} = h ν_{0}$

$6.63 \times 1.6 \times 10^{- 19} = 6.63 \times 10^{- 34} ν_{0}$

$ν_{0} = \frac{1.6 \times 10^{- 19}}{10^{- 34}}$

$ν_{0} = 1.6 \times 10^{15} Hz$

Q 8 :

The work function of a substance is 3.0 eV. The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately [2024]

215 nm
414 nm
400 nm
200 nm

1

2

3

4

(2)

For photoelectric effect: $λ \leq \frac{h c}{W_{e}}$

$λ \leq \frac{1240 nm - eV}{3 eV}$

$λ \leq 413.33 nm$

$λ_{\max} \approx 414 nm$

Q 9 :

When a metal surface is illuminated by light of wavelength $λ$ , the stopping potential is 8V. When the same surface is illuminated by light of wavelength $3 λ$ , stopping potential is 2V. The threshold wavelength for this surface is [2024]

$9 λ$
$3 λ$
$4.5 λ$
$5 λ$

1

2

3

4

(1)

$E = ϕ + K_{\max}$

$ϕ = \frac{h c}{λ_{0}}$

$K_{\max} = e V_{0}$

$8 e = \frac{h c}{λ} - \frac{h c}{λ_{0}}$ ...(i)

$2 e = \frac{h c}{3 λ} - \frac{h c}{λ_{0}}$ ...(ii)

On solving (i) and (ii) $λ_{0} = 9 λ$

Q 10 :

In a photoelectric effect experiment a light of frequency 1.5 times the threshold frequency is made to fall on the surface of photosensitive material. Now if the frequency is halved and intensity is doubled, the number of photo electrons emitted will be [2024]

Doubled
Quadrupled
Zero
Halved

1

2

3

4

(3)

Since $\frac{f}{2} < f_{0}$

i.e. the incident frequency is less than threshold frequency. Hence there will be no emission of photoelectrons.

$\Rightarrow$ current = 0

Q 11 :

Which figure shows the correct variation of applied potential difference (V) with photoelectric current (i) at two different intensities of light ( $I_{1} < I_{2}$ ) of same wavelengths? [2024]

1

2

3

4

(1)

Saturation current depends on intensity of incident light.
Also, according to question, both have same wavelength.
Hence stopping potential will remain same, it means $K E_{m a x}$ will be same.
Since $I_{2} > I_{1}$ , hence saturation current corresponding to $I_{2}$ will be greater than that corresponding to $I_{1}$ .

Q 12 :

Given below are two statements:

Statement I: Figure shows the variation of stopping potential with frequency (ν) for the two photosensitive materials $M_{1}$ and $M_{2}$ . The slope gives value of $\frac{h}{e}$ , where h is Planck’s constant, e is the charge of an electron.

Statement II: $M_{2}$ will emit photoelectrons of greater kinetic energy for the incident radiation having the same frequency.

In the light of the above statements, choose the most appropriate answer from the options given below. [2024]

Statement I is incorrect but Statement II is correct
Both Statement I and Statement II are incorrect
Both Statement I and Statement II are correct
Statement I is correct and Statement II is incorrect

1

2

3

4

(4)

$e V_{s} = h ν + ϕ \Rightarrow V_{s} = \frac{h}{e} ν + \frac{ϕ}{e}$

slope = $\frac{h}{e}$

Work function of $M_{2}$ is higher than $M_{1}$ so kinetic energy of emitted electron is less for $M_{2}$

Q 13 :

For the photoelectric effect, the maximum kinetic energy ( $E_{k}$ ) of the photoelectrons is plotted against the frequency ( $v$ ) of the incident photons as shown in the figure. The slope of the graph gives [2024]

Ratio of Planck’s constant to electric charge
Work function of the metal
Charge of electron
Planck’s constant

1

2

3

4

(4)

We know that

$E = K . E . + ϕ_{0}$

$h ν = K . E . + ϕ_{0}$

$K . E = h ν - ϕ_{0}$

Slope of kinetic energy versus frequency curve will be equal to slope $h .$

Q 14 :

The work functions of cesium (Cs) and lithium (Li) metals are 1.9 eV and 2.5 eV, respectively. If we incident a light of wavelength 550 nm on these two metal surfaces, then photo-electric effect is possible for the case of [2025]

Li only
Cs only
Neither Cs nor Li
Both Cs and Li

1

2

3

4

(2)

E (energy of incident photon) $= \frac{1240}{550} = 2.25 eV$

$E > ϕ_{Cs}, E < ϕ_{Li}$

$∴$ Only cesium will show photoelectric effect.

Q 15 :

A light source of wavelength $λ$ illuminates a metal surface and electrons are ejected with maximum kinetic energy of 2 eV. If the same surface is illuminated by a light source of wavelength $\frac{λ}{2}$ , then the maximum kinetic energy of ejected electrons will be (The work function of metal is 1 eV) [2025]

2 eV
6 eV
5 eV
3 eV

1

2

3

4

(3)

Einstein's photoelectric equation

$KE = \frac{h c}{λ} - ϕ_{0}$

$2 eV = \frac{h c}{λ} - 1 eV$

$\frac{h c}{λ} = 3 eV$

$KE = \frac{h c}{(λ / 2)} - ϕ_{0} = 6 eV - 1 eV = 5 eV$

Q 16 :

In photoelectric effect an em-wave is incident on a metal surface and electrons are ejected from the surface. If the work function of the metal is 2.14 eV and stopping potential is 2 V, what is the wavelength of the em-wave?

(Given hc = 1242 eVm where h is the Planck's constant and c is the speed of light in vacuum.) [2025]

400 nm
600 nm
200 nm
300 nm

1

2

3

4

(4)

Using photoelectric equation ${eV}_{s} = E$

2 eV = E – 2.14 eV $\Rightarrow$ E = 4.14 eV

$E = \frac{h c}{λ} \Rightarrow λ = \frac{1242}{4.14} = 300 nm$

Q 17 :

In photoelectric effect, the stopping potential ( $V_{0}$ ) v/s frequency ( $v$ ) curve is plotted.

(h is the Planck's constant and $ϕ_{0}$ is work function of metal)

(A) $V_{0}$ v/s $v$ is linear

(B) The slope of $V_{0}$ v/s $v$ curve = $\frac{ϕ_{0}}{h}$

(C) h constant is related to the slope of $V_{0}$ v/s $v$ line

(D) The value of electric charge of electron is not required to determine h using the $V_{0}$ v/s $v$ curve.

(E) The work function can be estimated without knowing the value of h.

Choose the correct answer from the options given below: [2025]

(A), (B) and (C) only
(C) and (D) only
(A), (C) and (E) only
(D) and (E) only

1

2

3

4

(3)

$h v = ϕ + {KE}_{\max}$

${KE}_{\max} = {eV}_{0}$

$\Rightarrow V_{0} = (\frac{h}{e}) v - \frac{ϕ_{0}}{e}$

So slope is constant $= \frac{h}{e}$

and intercept is $- ve (\frac{ϕ}{e})$

$\Rightarrow$ Option (A) is correct, Option (B) is wrong.

$\Rightarrow$ Option (C) is correct, option (D) is wrong.

$\Rightarrow$ Option (E) is correct.

(A), (C) and (E) are correct.

Q 18 :

Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion(A) : Emission of electrons in photoelectric effect can be suppressed by applying a sufficiently negative electron potential to the photoemissive substance.

Reason (R) : A negative electric potential, which stops the emission of electrons from the surface of a photoemissive substance, varies linearly with frequency of incident radiation.

In the light of the above statements, choose the most appropriate answer from the options given below: [2025]

(A) is false but (R) is true.
(A) is true but (R) is false.
Both (A) and (R) are true and (R) is the correct explanation of (A).
Both (A) and (R) are true but (R) is Not the correct explanation of (A).

1

2

3

4

(4)

Negative potential will slow the electrons and if it is sufficient, it will make the photocurrent zero.

Q 19 :

In an experiment with photoelectric effect, the stopping potential. [2025]

increases with increase in the wavelength of the incident light.
increases with increase in the intensity of the incident light.
is $(\frac{1}{e})$ times the maximum kinetic energy of the emitted photoelectrons.
decreases with increase in the intensity of the incident light.

1

2

3

4

(3)

From Einstein photoelectric equation

$\frac{h c}{λ} = ϕ + {eV}_{S}$

Maximum K.E. $= {(K)}_{\max} = {eV}_{S}$

So, $V_{S} = \frac{{(K)}_{\max}}{e}$

Q 20 :

A monochromatic light is incident on a metallic plate having work function $ϕ$ . An electron, emitted normally to the plate from a point A with maximum kinetic energy, enterss a constant magnetic field, perpendicular to the initial velocity of electron. The electron passes through a curve and hits back the plate at a point B. The distance between A and B is

(Given: The magnitude of charge of an electron is e and mass is m, h is Planck's constant and c is velocity of light. Take the magnetic field exists throughout the path of electron) [2025]

$\sqrt{2 m (\frac{h c}{λ} - ϕ)} / e B$
$\sqrt{m (\frac{h c}{λ} - ϕ)} / e B$
$\sqrt{8 m (\frac{h c}{λ} - ϕ)} / e B$
$2 \sqrt{m (\frac{h c}{λ} - ϕ)} / e B$

1

2

3

4

(3)

${KE}_{\max} = \frac{h c}{λ} - ϕ$

$p = \sqrt{2 m K_{\max}}$

$p = \sqrt{2 m (\frac{h c}{λ} - ϕ)}$

$d_{A B} = 2 R = 2 [\frac{p}{q B}]$

$d_{A B} = \frac{2 \sqrt{2 m (\frac{h c}{λ} - ϕ)}}{e B} = \frac{\sqrt{8 m (\frac{h c}{λ} - ϕ)}}{e B}$

Q 21 :

The work function of metal is 3 eV. The colour of the visible light that is required to cause emission of photoelectrons is [2025]

Green
Blue
Red
Yellow

1

2

3

4

(2)

For emission : $\frac{h c}{λ} > ϕ$

$λ < \frac{h c}{ϕ} \Rightarrow λ < \frac{1242}{3} nm$

Q 22 :

Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R)

Assertion (A) : In photoelectric effect, on increasing the intensity of incident light the stopping potential increases.

Reason (R) : Increase in intensity of light increases the rate of photoelectrons emitted, provided the frequency of incident light is greater than threshold frequency.

In the light of the above statements, choose the correct answer from the options given below: {2025]

Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
(A) is false but (R) is true.
(A) is true but (R) is false.
Both (A) and (R) are true and (R) is the correct explanation of (A).

1

2

3

4

(2)

Stopping potential, $V_{S} = \frac{h v - ϕ}{e}$ so stopping potential doesn't depend on intensity, stopping potential depends on frequency.

Intensity $\propto$ number of photons.

On increasing intensity, no. of photons per sec increases and so the no. of electrons.

Q 23 :

From the photoelectric effect experiment, following observations are made. Identify “which of these are correct.” [2023]

A. The stopping potential depends only on the work function of the metal.
B. The saturation current increases as the intensity of incident light increases.
C. The maximum kinetic energy of a photoelectron depends on the intensity of the incident light.
D. Photoelectric effect can be explained using wave theory of light.

Choose the correct answer from the options given below:

A, B, D only
B only
A, C, D only
B, C only

1

2

3

4

(2)

(A) Stopping potential depends on both frequency of light and work function.

(B) Saturation current $\propto$ intensity of light

(C) Maximum KE depends on frequency

(D) Photoelectric effect is explained using particle theory.

Q 24 :

Given below are two statements: [2023]

Statement I: Stopping potential in photoelectric effect does not depend on the power of the light source.

Statement II: For a given metal, the maximum kinetic energy of the photoelectron depends on the wavelength of the incident light.

In the light of above statements, choose the most appropriate answer from the options given below.

Both Statement I and Statement II are incorrect
Statement I is correct but statement II is incorrect
Both statement I and statement II are correct
Statement I is incorrect but statement II is correct

1

2

3

4

(3)

Stopping potential $V_{s} = \frac{K E_{\max}}{e}$

$V_{s} = \frac{\frac{h C}{λ} - ϕ}{e}$

Stopping potential does not depend on intensity or power of light used; it only depends on the frequency or wavelength of the incident light.

So both statements I and II are correct.

Q 25 :

The threshold wavelength for photoelectric emission from a material is 5500 $Å$ . Photoelectrons will be emitted, when this material is illuminated with monochromatic radiation from a ______ [2023]

A. 75 W infra-red lamp
B. 10 W infra-red lamp
C. 75 W ultra-violet lamp
D. 10 W ultra-violet lamp

Choose the correct answer from the options given below:

B and C only
A and D only
C only
C and D only

1

2

3

4

(4)

$λ < 5500 Å for photoelectric emission$

$λ_{u v} < 5500 Å$

Q 26 :

If the two metals A and B are exposed to radiation of wavelength 350 nm. The work functions of metals A and B are 4.8 eV and 2.2 eV. Then choose the correct option. [2023]

Metal B will not emit photo-electrons
Both metals A and B will emit photo-electrons
Both metals A and B will not emit photo-electrons
Metal A will not emit photo-electrons

1

2

3

4

(4)

$ϕ = \frac{h c}{λ} = \frac{1240}{350} eV = 3.54 eV$

$∴$ $Only metal B will emit photoelectron.$

Q 27 :

The threshold frequency of metal is $f_{0}$ . When the light of frequency $2 f_{0}$ is incident on the metal plate, the maximum velocity of photoelectron is $v_{1}$ . When the frequency of incident radiation is increased to $5 f_{0}$ , the maximum velocity of photoelectrons emitted is $v_{2}$ . The ratio of $v_{1}$ to $v_{2}$ is [2023]

$\frac{v_{1}}{v_{2}} = \frac{1}{2}$
$\frac{v_{1}}{v_{2}} = \frac{1}{8}$
$\frac{v_{1}}{v_{2}} = \frac{1}{16}$
$\frac{v_{1}}{v_{2}} = \frac{1}{4}$

1

2

3

4

(1)

$K_{\max} = h f - h f_{0}$

For $f = 2 f_{0}$

$\frac{1}{2} m v_{1}^{2} = 2 h f_{0} - h f_{0} = h f_{0} \dots (i)$

For $f = 5 f_{0}$

$\frac{1}{2} m v_{2}^{2} = 5 h f_{0} - h f_{0} = 4 h f_{0} \dots (i i)$

From (i) and (ii),

$\Rightarrow \frac{v_{1}}{v_{2}} = \frac{1}{2}$

Q 28 :

The work functions of Aluminium and Gold are 4.1 eV and 5.1 eV respectively. The ratio of the slope of the stopping potential versus frequency plot for Gold to that of Aluminium is [2023]

1.24
2
1
1.5

1

2

3

4

(3)

$e V_{s} = k_{\max}$

$V_{s} = {\frac{h}{e}} f + {\frac{- ϕ}{e}}$

$Slope is independent of nature of metal$

$slope {(V_{s})}^{Gold} = slope {(V_{s})}^{Aluminium}$

Q 29 :

In photoelectric effect [2023]

A. The photocurrent is proportional to the intensity of the incident radiation.

B. Maximum kinetic energy with which photoelectrons are emitted depends on the intensity of incident light.

C. Max. K.E. with which photoelectrons are emitted depends on the frequency of incident light.

D. The emission of photoelectrons require a minimum threshold intensity of incident radiation.

E. Max. K.E. of the photoelectrons is independent of the frequency of the incident light.

Choose the correct answer from the options given below:

A and E only
A and C only
A and B only
B and C only

1

2

3

4

(2)

$Intensity of light \propto number of photons \propto no. of photoelectrons \propto photocurrent$

$So, A is correct$

$K E_{\max} = h ν - ϕ$

$K E_{\max} depends on frequency$

$So, C is correct$

$So, A and C are correct$

Q 30 :

The variation of stopping potential $(V_{0})$ as a function of the frequency $(ν)$ of the incident light for a metal is shown in figure. The work function of the surface is [2023]

18.6 eV
2.98 eV
2.07 eV
1.36 eV

1

2

3

4

(3)

$e V_{0} = h ν - ϕ$

$0 = h ν - ϕ$

$ϕ = h ν = 6.6 \times 10^{- 34} \times 5 \times 10^{14} = 33 \times 10^{- 20} J$

$ϕ = \frac{33 \times 10^{- 20}}{1.6 \times 10^{- 19}} = 2.07 eV$

Topic Question Set

Q 2 :

Which of the following statement is not true about stopping potential $(V_{0})$ ? [2024]

Q 3 :

In photoelectric experiment energy of 2.48 eV irradiates a photo sensitive material. The stopping potential was measured to be 0.5 V. Work function of the photo sensitive material is : [2024]

Q 4 :

When UV light of wavelength 300 nm is incident on the metal surface having work function 2.13 eV, electron emission takes place. The stopping potential is [2024]

Q 5 :

UV light of 4.13 eV is incident on a photosensitive metal surface having work function 3.13 eV. The maximum kinetic energy of ejected photoelectrons will be [2024]

Q 6 :

A convex lens of focal length 40 cm forms an image of an extended source of light on a photoelectric cell. A current $I$ is produced. The lens is replaced by another convex lens having the same diameter but focal length 20 cm. The photoelectric current now is [2024]

Q 7 :

The threshold frequency of a metal with work function 6.63eV is [2024]

Q 8 :

The work function of a substance is 3.0 eV. The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately [2024]

Q 9 :

When a metal surface is illuminated by light of wavelength $λ$ , the stopping potential is 8V. When the same surface is illuminated by light of wavelength $3 λ$ , stopping potential is 2V. The threshold wavelength for this surface is [2024]

Q 10 :

In a photoelectric effect experiment a light of frequency 1.5 times the threshold frequency is made to fall on the surface of photosensitive material. Now if the frequency is halved and intensity is doubled, the number of photo electrons emitted will be [2024]

Q 11 :

Which figure shows the correct variation of applied potential difference (V) with photoelectric current (i) at two different intensities of light ( $I_{1} < I_{2}$ ) of same wavelengths? [2024]

Q 13 :

For the photoelectric effect, the maximum kinetic energy ( $E_{k}$ ) of the photoelectrons is plotted against the frequency ( $v$ ) of the incident photons as shown in the figure. The slope of the graph gives [2024]

Q 14 :

The work functions of cesium (Cs) and lithium (Li) metals are 1.9 eV and 2.5 eV, respectively. If we incident a light of wavelength 550 nm on these two metal surfaces, then photo-electric effect is possible for the case of [2025]

Q 19 :

In an experiment with photoelectric effect, the stopping potential. [2025]

Q 21 :

The work function of metal is 3 eV. The colour of the visible light that is required to cause emission of photoelectrons is [2025]

Q 26 :

If the two metals A and B are exposed to radiation of wavelength 350 nm. The work functions of metals A and B are 4.8 eV and 2.2 eV. Then choose the correct option. [2023]

Q 28 :

The work functions of Aluminium and Gold are 4.1 eV and 5.1 eV respectively. The ratio of the slope of the stopping potential versus frequency plot for Gold to that of Aluminium is [2023]

Q 30 :

The variation of stopping potential $(V_{0})$ as a function of the frequency $(ν)$ of the incident light for a metal is shown in figure. The work function of the surface is [2023]

Want Us to Email you About Special Offers & Updates?

Topic Question Set

Q 2 : Which of the following statement is not true about stopping potential (V0) ? [2024]

Q 3 : In photoelectric experiment energy of 2.48 eV irradiates a photo sensitive material. The stopping potential was measured to be 0.5 V. Work function of the photo sensitive material is : [2024]

Q 4 : When UV light of wavelength 300 nm is incident on the metal surface having work function 2.13 eV, electron emission takes place. The stopping potential is [2024]

Q 5 : UV light of 4.13 eV is incident on a photosensitive metal surface having work function 3.13 eV. The maximum kinetic energy of ejected photoelectrons will be [2024]

Q 6 : A convex lens of focal length 40 cm forms an image of an extended source of light on a photoelectric cell. A current I is produced. The lens is replaced by another convex lens having the same diameter but focal length 20 cm. The photoelectric current now is [2024]

Q 7 : The threshold frequency of a metal with work function 6.63eV is [2024]

Q 8 : The work function of a substance is 3.0 eV. The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately [2024]

Q 9 : When a metal surface is illuminated by light of wavelength λ, the stopping potential is 8V. When the same surface is illuminated by light of wavelength 3λ, stopping potential is 2V. The threshold wavelength for this surface is [2024]

Q 10 : In a photoelectric effect experiment a light of frequency 1.5 times the threshold frequency is made to fall on the surface of photosensitive material. Now if the frequency is halved and intensity is doubled, the number of photo electrons emitted will be [2024]

Q 11 : Which figure shows the correct variation of applied potential difference (V) with photoelectric current (i) at two different intensities of light (I1<I2) of same wavelengths? [2024]

Q 13 : For the photoelectric effect, the maximum kinetic energy (Ek) of the photoelectrons is plotted against the frequency (v) of the incident photons as shown in the figure. The slope of the graph gives [2024]

Q 14 : The work functions of cesium (Cs) and lithium (Li) metals are 1.9 eV and 2.5 eV, respectively. If we incident a light of wavelength 550 nm on these two metal surfaces, then photo-electric effect is possible for the case of [2025]

Q 19 : In an experiment with photoelectric effect, the stopping potential. [2025]

Q 21 : The work function of metal is 3 eV. The colour of the visible light that is required to cause emission of photoelectrons is [2025]

Q 26 : If the two metals A and B are exposed to radiation of wavelength 350 nm. The work functions of metals A and B are 4.8 eV and 2.2 eV. Then choose the correct option. [2023]

Q 28 : The work functions of Aluminium and Gold are 4.1 eV and 5.1 eV respectively. The ratio of the slope of the stopping potential versus frequency plot for Gold to that of Aluminium is [2023]

Q 30 : The variation of stopping potential (V0) as a function of the frequency (ν) of the incident light for a metal is shown in figure. The work function of the surface is [2023]

Want Us to Email you About Special Offers & Updates?

Q 2 :

Which of the following statement is not true about stopping potential $(V_{0})$ ? [2024]

Q 3 :

In photoelectric experiment energy of 2.48 eV irradiates a photo sensitive material. The stopping potential was measured to be 0.5 V. Work function of the photo sensitive material is : [2024]

Q 4 :

When UV light of wavelength 300 nm is incident on the metal surface having work function 2.13 eV, electron emission takes place. The stopping potential is [2024]

Q 5 :

UV light of 4.13 eV is incident on a photosensitive metal surface having work function 3.13 eV. The maximum kinetic energy of ejected photoelectrons will be [2024]

Q 6 :

A convex lens of focal length 40 cm forms an image of an extended source of light on a photoelectric cell. A current $I$ is produced. The lens is replaced by another convex lens having the same diameter but focal length 20 cm. The photoelectric current now is [2024]

Q 7 :

The threshold frequency of a metal with work function 6.63eV is [2024]

Q 8 :

The work function of a substance is 3.0 eV. The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately [2024]

Q 9 :

When a metal surface is illuminated by light of wavelength $λ$ , the stopping potential is 8V. When the same surface is illuminated by light of wavelength $3 λ$ , stopping potential is 2V. The threshold wavelength for this surface is [2024]

Q 10 :

In a photoelectric effect experiment a light of frequency 1.5 times the threshold frequency is made to fall on the surface of photosensitive material. Now if the frequency is halved and intensity is doubled, the number of photo electrons emitted will be [2024]

Q 11 :

Which figure shows the correct variation of applied potential difference (V) with photoelectric current (i) at two different intensities of light ( $I_{1} < I_{2}$ ) of same wavelengths? [2024]

Q 13 :

For the photoelectric effect, the maximum kinetic energy ( $E_{k}$ ) of the photoelectrons is plotted against the frequency ( $v$ ) of the incident photons as shown in the figure. The slope of the graph gives [2024]

Q 14 :

The work functions of cesium (Cs) and lithium (Li) metals are 1.9 eV and 2.5 eV, respectively. If we incident a light of wavelength 550 nm on these two metal surfaces, then photo-electric effect is possible for the case of [2025]

Q 19 :

In an experiment with photoelectric effect, the stopping potential. [2025]

Q 21 :

The work function of metal is 3 eV. The colour of the visible light that is required to cause emission of photoelectrons is [2025]

Q 26 :

If the two metals A and B are exposed to radiation of wavelength 350 nm. The work functions of metals A and B are 4.8 eV and 2.2 eV. Then choose the correct option. [2023]

Q 28 :

The work functions of Aluminium and Gold are 4.1 eV and 5.1 eV respectively. The ratio of the slope of the stopping potential versus frequency plot for Gold to that of Aluminium is [2023]

Q 30 :

The variation of stopping potential $(V_{0})$ as a function of the frequency $(ν)$ of the incident light for a metal is shown in figure. The work function of the surface is [2023]