Previous Year Questions (2021-24): Duel Nature of Matter and Radiation | Physics for JEE Main & Advanced PDF Download

 Page 1


Previous Year Questions (2021-24): 
Duel Nature of Matter and Radiation 
2024 
 
Q1 - 2024 (01 Feb Shift 1) 
The de Broglie wavelengths of a proton and an ?? particle are ?? and 2 ?? 
respectively. The ratio of the velocities of proton and ?? particle will be : 
(1) 1 : 8 
(2) 1 : 2 
(3) 4 : 1 
(4) 8 : 1 
Q2 - 2024 (01 Feb Shift 2) 
Monochromatic light of frequency 6 × 10
14
 Hz is produced by a laser. The power 
emitted is 2 × 10
- 3
 W. How many photons per second on an average, are 
emitted by the source? 
(Given h = 6 . 63 × 10
- 34
Js ) 
(1) 9 × 10
18
 
(2) 6 × 10
15
 
(3) 5 × 10
15
 
(4) 7 × 10
16
 
Q3 - 2024 (27 Jan Shift 2) 
The threshold frequency of a metal with work function 6 . 6 3 e V is : 
(1) 16 × 10
15
 Hz 
(2) 16 × 10
12
 Hz 
(3) 1 . 6 × 10
12
 Hz 
(4) 1 . 6 × 10
15
 Hz 
Page 2


Previous Year Questions (2021-24): 
Duel Nature of Matter and Radiation 
2024 
 
Q1 - 2024 (01 Feb Shift 1) 
The de Broglie wavelengths of a proton and an ?? particle are ?? and 2 ?? 
respectively. The ratio of the velocities of proton and ?? particle will be : 
(1) 1 : 8 
(2) 1 : 2 
(3) 4 : 1 
(4) 8 : 1 
Q2 - 2024 (01 Feb Shift 2) 
Monochromatic light of frequency 6 × 10
14
 Hz is produced by a laser. The power 
emitted is 2 × 10
- 3
 W. How many photons per second on an average, are 
emitted by the source? 
(Given h = 6 . 63 × 10
- 34
Js ) 
(1) 9 × 10
18
 
(2) 6 × 10
15
 
(3) 5 × 10
15
 
(4) 7 × 10
16
 
Q3 - 2024 (27 Jan Shift 2) 
The threshold frequency of a metal with work function 6 . 6 3 e V is : 
(1) 16 × 10
15
 Hz 
(2) 16 × 10
12
 Hz 
(3) 1 . 6 × 10
12
 Hz 
(4) 1 . 6 × 10
15
 Hz 
Q4 - 2024 (29 Jan Shift 2) 
Two sources of light emit with a power of 200 W. The ratio of number of photons 
of visible light emitted by each source having wavelengths 300 nm and 500 nm 
respectively, will be : 
(1) 1 : 5 
(2) 1 : 3 
(3) 5 : 3 
(4) 3 : 5 
Q5 - 2024 (30 Jan Shift 1) 
The work function of a substance is 3 . 0 e V . The longest wavelength of light that 
can cause the emission of photoelectrons from this substance is approximately: 
(1) 215 nm 
(2) 414 nm 
(3) 400 nm 
(4) 200 nm 
Q6 - 2024 (30 Jan Shift 2) 
For the photoelectric effect, the maximum kinetic energy ( ?? ?? ) of the 
photoelectrons is plotted against the frequency (v) of the incident photons as 
shown in figure. The slope of the graph gives 
 
(1) Ratio of Planck's constant to electric charge 
(2) Work function of the metal 
Page 3


Previous Year Questions (2021-24): 
Duel Nature of Matter and Radiation 
2024 
 
Q1 - 2024 (01 Feb Shift 1) 
The de Broglie wavelengths of a proton and an ?? particle are ?? and 2 ?? 
respectively. The ratio of the velocities of proton and ?? particle will be : 
(1) 1 : 8 
(2) 1 : 2 
(3) 4 : 1 
(4) 8 : 1 
Q2 - 2024 (01 Feb Shift 2) 
Monochromatic light of frequency 6 × 10
14
 Hz is produced by a laser. The power 
emitted is 2 × 10
- 3
 W. How many photons per second on an average, are 
emitted by the source? 
(Given h = 6 . 63 × 10
- 34
Js ) 
(1) 9 × 10
18
 
(2) 6 × 10
15
 
(3) 5 × 10
15
 
(4) 7 × 10
16
 
Q3 - 2024 (27 Jan Shift 2) 
The threshold frequency of a metal with work function 6 . 6 3 e V is : 
(1) 16 × 10
15
 Hz 
(2) 16 × 10
12
 Hz 
(3) 1 . 6 × 10
12
 Hz 
(4) 1 . 6 × 10
15
 Hz 
Q4 - 2024 (29 Jan Shift 2) 
Two sources of light emit with a power of 200 W. The ratio of number of photons 
of visible light emitted by each source having wavelengths 300 nm and 500 nm 
respectively, will be : 
(1) 1 : 5 
(2) 1 : 3 
(3) 5 : 3 
(4) 3 : 5 
Q5 - 2024 (30 Jan Shift 1) 
The work function of a substance is 3 . 0 e V . The longest wavelength of light that 
can cause the emission of photoelectrons from this substance is approximately: 
(1) 215 nm 
(2) 414 nm 
(3) 400 nm 
(4) 200 nm 
Q6 - 2024 (30 Jan Shift 2) 
For the photoelectric effect, the maximum kinetic energy ( ?? ?? ) of the 
photoelectrons is plotted against the frequency (v) of the incident photons as 
shown in figure. The slope of the graph gives 
 
(1) Ratio of Planck's constant to electric charge 
(2) Work function of the metal 
(3) Charge of electron 
(4) Planck's constant 
Q7 - 2024 (31 Jan Shift 1) 
If the wavelength of the first member of Lyman series of hydrogen is ?? . The 
wavelength of the second member will be 
(1) 
27
32
?? 
(2) 
32
27
?? 
(3) 
27
5
?? 
(4) 
5
27
?? 
Q8 - 2024 (31 Jan Shift 1) 
When a metal surface is illuminated by light of wavelength ?? , the stopping 
potential is 8 V. When the same surface is illuminated by light of wavelength 3 ?? , 
stopping potential is 2 V. The threshold wavelength for this surface is : 
(1) 5 ?? 
(2) 3 ?? 
(3) 9 ?? 
(4) 4 . 5 ?? 
Q9 - 2024 (31 Jan Shift 2) 
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: 
(1) Doubled 
(2) Quadrupled 
(3) Zero 
(4) Halved 
 
Page 4


Previous Year Questions (2021-24): 
Duel Nature of Matter and Radiation 
2024 
 
Q1 - 2024 (01 Feb Shift 1) 
The de Broglie wavelengths of a proton and an ?? particle are ?? and 2 ?? 
respectively. The ratio of the velocities of proton and ?? particle will be : 
(1) 1 : 8 
(2) 1 : 2 
(3) 4 : 1 
(4) 8 : 1 
Q2 - 2024 (01 Feb Shift 2) 
Monochromatic light of frequency 6 × 10
14
 Hz is produced by a laser. The power 
emitted is 2 × 10
- 3
 W. How many photons per second on an average, are 
emitted by the source? 
(Given h = 6 . 63 × 10
- 34
Js ) 
(1) 9 × 10
18
 
(2) 6 × 10
15
 
(3) 5 × 10
15
 
(4) 7 × 10
16
 
Q3 - 2024 (27 Jan Shift 2) 
The threshold frequency of a metal with work function 6 . 6 3 e V is : 
(1) 16 × 10
15
 Hz 
(2) 16 × 10
12
 Hz 
(3) 1 . 6 × 10
12
 Hz 
(4) 1 . 6 × 10
15
 Hz 
Q4 - 2024 (29 Jan Shift 2) 
Two sources of light emit with a power of 200 W. The ratio of number of photons 
of visible light emitted by each source having wavelengths 300 nm and 500 nm 
respectively, will be : 
(1) 1 : 5 
(2) 1 : 3 
(3) 5 : 3 
(4) 3 : 5 
Q5 - 2024 (30 Jan Shift 1) 
The work function of a substance is 3 . 0 e V . The longest wavelength of light that 
can cause the emission of photoelectrons from this substance is approximately: 
(1) 215 nm 
(2) 414 nm 
(3) 400 nm 
(4) 200 nm 
Q6 - 2024 (30 Jan Shift 2) 
For the photoelectric effect, the maximum kinetic energy ( ?? ?? ) of the 
photoelectrons is plotted against the frequency (v) of the incident photons as 
shown in figure. The slope of the graph gives 
 
(1) Ratio of Planck's constant to electric charge 
(2) Work function of the metal 
(3) Charge of electron 
(4) Planck's constant 
Q7 - 2024 (31 Jan Shift 1) 
If the wavelength of the first member of Lyman series of hydrogen is ?? . The 
wavelength of the second member will be 
(1) 
27
32
?? 
(2) 
32
27
?? 
(3) 
27
5
?? 
(4) 
5
27
?? 
Q8 - 2024 (31 Jan Shift 1) 
When a metal surface is illuminated by light of wavelength ?? , the stopping 
potential is 8 V. When the same surface is illuminated by light of wavelength 3 ?? , 
stopping potential is 2 V. The threshold wavelength for this surface is : 
(1) 5 ?? 
(2) 3 ?? 
(3) 9 ?? 
(4) 4 . 5 ?? 
Q9 - 2024 (31 Jan Shift 2) 
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: 
(1) Doubled 
(2) Quadrupled 
(3) Zero 
(4) Halved 
 
Answer Key 
Q1 (4)  
Q2 (3)  
Q3 (4)  
Q4 (4) 
Q5 (2)  
Q6 (4)  
Q7 (1)  
Q8 (3) 
Q9 (3) 
Solutions 
Q1 
?? =
h
p
=
h
mv
? v =
h
m ?? 
v
p
v
?? =
m
?? m
p
×
?? ?? ?? p
 
= 4 × 2 = 8 
Q2 
P = nh ?? 
n =
P
hv
=
2 × 10
- 3
6 . 63 × 10
- 34
× 6 × 10
14
 
Page 5


Previous Year Questions (2021-24): 
Duel Nature of Matter and Radiation 
2024 
 
Q1 - 2024 (01 Feb Shift 1) 
The de Broglie wavelengths of a proton and an ?? particle are ?? and 2 ?? 
respectively. The ratio of the velocities of proton and ?? particle will be : 
(1) 1 : 8 
(2) 1 : 2 
(3) 4 : 1 
(4) 8 : 1 
Q2 - 2024 (01 Feb Shift 2) 
Monochromatic light of frequency 6 × 10
14
 Hz is produced by a laser. The power 
emitted is 2 × 10
- 3
 W. How many photons per second on an average, are 
emitted by the source? 
(Given h = 6 . 63 × 10
- 34
Js ) 
(1) 9 × 10
18
 
(2) 6 × 10
15
 
(3) 5 × 10
15
 
(4) 7 × 10
16
 
Q3 - 2024 (27 Jan Shift 2) 
The threshold frequency of a metal with work function 6 . 6 3 e V is : 
(1) 16 × 10
15
 Hz 
(2) 16 × 10
12
 Hz 
(3) 1 . 6 × 10
12
 Hz 
(4) 1 . 6 × 10
15
 Hz 
Q4 - 2024 (29 Jan Shift 2) 
Two sources of light emit with a power of 200 W. The ratio of number of photons 
of visible light emitted by each source having wavelengths 300 nm and 500 nm 
respectively, will be : 
(1) 1 : 5 
(2) 1 : 3 
(3) 5 : 3 
(4) 3 : 5 
Q5 - 2024 (30 Jan Shift 1) 
The work function of a substance is 3 . 0 e V . The longest wavelength of light that 
can cause the emission of photoelectrons from this substance is approximately: 
(1) 215 nm 
(2) 414 nm 
(3) 400 nm 
(4) 200 nm 
Q6 - 2024 (30 Jan Shift 2) 
For the photoelectric effect, the maximum kinetic energy ( ?? ?? ) of the 
photoelectrons is plotted against the frequency (v) of the incident photons as 
shown in figure. The slope of the graph gives 
 
(1) Ratio of Planck's constant to electric charge 
(2) Work function of the metal 
(3) Charge of electron 
(4) Planck's constant 
Q7 - 2024 (31 Jan Shift 1) 
If the wavelength of the first member of Lyman series of hydrogen is ?? . The 
wavelength of the second member will be 
(1) 
27
32
?? 
(2) 
32
27
?? 
(3) 
27
5
?? 
(4) 
5
27
?? 
Q8 - 2024 (31 Jan Shift 1) 
When a metal surface is illuminated by light of wavelength ?? , the stopping 
potential is 8 V. When the same surface is illuminated by light of wavelength 3 ?? , 
stopping potential is 2 V. The threshold wavelength for this surface is : 
(1) 5 ?? 
(2) 3 ?? 
(3) 9 ?? 
(4) 4 . 5 ?? 
Q9 - 2024 (31 Jan Shift 2) 
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: 
(1) Doubled 
(2) Quadrupled 
(3) Zero 
(4) Halved 
 
Answer Key 
Q1 (4)  
Q2 (3)  
Q3 (4)  
Q4 (4) 
Q5 (2)  
Q6 (4)  
Q7 (1)  
Q8 (3) 
Q9 (3) 
Solutions 
Q1 
?? =
h
p
=
h
mv
? v =
h
m ?? 
v
p
v
?? =
m
?? m
p
×
?? ?? ?? p
 
= 4 × 2 = 8 
Q2 
P = nh ?? 
n =
P
hv
=
2 × 10
- 3
6 . 63 × 10
- 34
× 6 × 10
14
 
= 5 × 10
15
 
Q3 
?? 0
= h ?? 0
 
6 . 63 × 1 . 6 × 10
- 19
= 6 . 63 × 10
- 34
?? 0
 
?? 0
=
1 . 6 × 10
- 19
10
- 34
 
?? 0
= 1 . 6 × 10
15
 Hz 
Q4 
n
1
×
hc
?? 1
= 200 
n
2
×
hc
?? 2
= 200 
n
1
n
2
=
?? 1
?? 2
=
300
500
 
n
1
n
2
=
3
5
 
Q5 
For P.E.E. : ?? =
h ?? ?? ?? 
?? =
1240 nm - eV
3 e V
 
?? = 413 . 33 nm 
?? m a x
˜ 414 nm for P.E.E. 
Q6 
K.E. = hf - ?? 
ta n ? ?? = h 
Q7 
1
?? =
13 . 6 ?? 2
h ?? [
1
1
2
-
1
2
2
] … (i)