Dual Nature of Radiation and Matter: JEE Mains Previous Year Questions (2021-2024) | Physics for JEE Main & Advanced PDF Download

 Page 1


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 
Solution: (4) 
?? =
h
p
=
h
mv
? v =
h
m?? 
v
p
v
?? =
m
?? m
p
×
?? ?? ?? p
 
= 4 × 2 = 8 
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
 
Solution: (3) 
P = nh?? 
n =
P
hv
=
2 × 10
-3
6.63 × 10
-34
× 6 × 10
14
 
= 5 × 10
15
 
 
Page 2


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 
Solution: (4) 
?? =
h
p
=
h
mv
? v =
h
m?? 
v
p
v
?? =
m
?? m
p
×
?? ?? ?? p
 
= 4 × 2 = 8 
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
 
Solution: (3) 
P = nh?? 
n =
P
hv
=
2 × 10
-3
6.63 × 10
-34
× 6 × 10
14
 
= 5 × 10
15
 
 
Q3 - 2024 (27 Jan Shift 2) 
The threshold frequency of a metal with work function 6.63eVis : 
(1) 16 × 10
15
Hz 
(2) 16 × 10
12
Hz 
(3) 1.6 × 10
12
Hz 
(4) 1.6 × 10
15
Hz 
Solution: (4) 
?? 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 - 2024 (29 Jan Shift 2) 
Two sources of light emit with a power of 200W. The ratio of number of photons of 
visible light emitted by each source having wavelengths 300nm and 500nm respectively, 
will be : 
(1) 1 : 5 
(2) 1 : 3 
(3) 5 : 3 
(4) 3 : 5 
Solution: (4) 
n
1
×
hc
?? 1
= 200 
n
2
×
hc
?? 2
= 200 
n
1
n
2
=
?? 1
?? 2
=
300
500
 
n
1
n
2
=
3
5
 
 
Page 3


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 
Solution: (4) 
?? =
h
p
=
h
mv
? v =
h
m?? 
v
p
v
?? =
m
?? m
p
×
?? ?? ?? p
 
= 4 × 2 = 8 
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
 
Solution: (3) 
P = nh?? 
n =
P
hv
=
2 × 10
-3
6.63 × 10
-34
× 6 × 10
14
 
= 5 × 10
15
 
 
Q3 - 2024 (27 Jan Shift 2) 
The threshold frequency of a metal with work function 6.63eVis : 
(1) 16 × 10
15
Hz 
(2) 16 × 10
12
Hz 
(3) 1.6 × 10
12
Hz 
(4) 1.6 × 10
15
Hz 
Solution: (4) 
?? 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 - 2024 (29 Jan Shift 2) 
Two sources of light emit with a power of 200W. The ratio of number of photons of 
visible light emitted by each source having wavelengths 300nm and 500nm respectively, 
will be : 
(1) 1 : 5 
(2) 1 : 3 
(3) 5 : 3 
(4) 3 : 5 
Solution: (4) 
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 - 2024 (30 Jan Shift 1) 
The work function of a substance is 3.0eV. The longest wavelength of light that can 
cause the emission of photoelectrons from this substance is approximately: 
(1) 215nm 
(2) 414nm 
(3) 400nm 
(4) 200nm 
Solution: (2) 
For P.E.E. :?? =
h?? ?? ?? 
?? =
1240nm - eV
3eV
 
?? = 413.33nm 
?? max
˜ 414nmfor P.E.E. 
 
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 
Solution: (4) 
K.E. = hf -?? 
tan? ?? = h 
Page 4


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 
Solution: (4) 
?? =
h
p
=
h
mv
? v =
h
m?? 
v
p
v
?? =
m
?? m
p
×
?? ?? ?? p
 
= 4 × 2 = 8 
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
 
Solution: (3) 
P = nh?? 
n =
P
hv
=
2 × 10
-3
6.63 × 10
-34
× 6 × 10
14
 
= 5 × 10
15
 
 
Q3 - 2024 (27 Jan Shift 2) 
The threshold frequency of a metal with work function 6.63eVis : 
(1) 16 × 10
15
Hz 
(2) 16 × 10
12
Hz 
(3) 1.6 × 10
12
Hz 
(4) 1.6 × 10
15
Hz 
Solution: (4) 
?? 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 - 2024 (29 Jan Shift 2) 
Two sources of light emit with a power of 200W. The ratio of number of photons of 
visible light emitted by each source having wavelengths 300nm and 500nm respectively, 
will be : 
(1) 1 : 5 
(2) 1 : 3 
(3) 5 : 3 
(4) 3 : 5 
Solution: (4) 
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 - 2024 (30 Jan Shift 1) 
The work function of a substance is 3.0eV. The longest wavelength of light that can 
cause the emission of photoelectrons from this substance is approximately: 
(1) 215nm 
(2) 414nm 
(3) 400nm 
(4) 200nm 
Solution: (2) 
For P.E.E. :?? =
h?? ?? ?? 
?? =
1240nm - eV
3eV
 
?? = 413.33nm 
?? max
˜ 414nmfor P.E.E. 
 
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 
Solution: (4) 
K.E. = hf -?? 
tan? ?? = h 
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
?? 
Solution: (1) 
1
?? =
13.6z
2
hc
 
1
1
2
-
1
2
2
 … (i) 
1
?? '
=
13.6z
2
hc
 
1
1
2
-
1
3
2
 … (ii) 
On dividing (i) \ & (ii) 
?? '
=
27
32
?? 
Q8 - 2024 (31 Jan Shift 1) 
When a metal surface is illuminated by light of wavelength ?? , the stopping potential is 8V. 
When the same surface is illuminated by light of wavelength 3?? , stopping potential is 2V. 
The threshold wavelength for this surface is : 
(1) 5?? 
(2) 3?? 
(3) 9?? 
(4) 4.5?? 
Solution: (3) 
E = ?? + K
max 
 
?? =
hc
?? 0
 
K
max 
= eV
0
 
Page 5


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 
Solution: (4) 
?? =
h
p
=
h
mv
? v =
h
m?? 
v
p
v
?? =
m
?? m
p
×
?? ?? ?? p
 
= 4 × 2 = 8 
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
 
Solution: (3) 
P = nh?? 
n =
P
hv
=
2 × 10
-3
6.63 × 10
-34
× 6 × 10
14
 
= 5 × 10
15
 
 
Q3 - 2024 (27 Jan Shift 2) 
The threshold frequency of a metal with work function 6.63eVis : 
(1) 16 × 10
15
Hz 
(2) 16 × 10
12
Hz 
(3) 1.6 × 10
12
Hz 
(4) 1.6 × 10
15
Hz 
Solution: (4) 
?? 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 - 2024 (29 Jan Shift 2) 
Two sources of light emit with a power of 200W. The ratio of number of photons of 
visible light emitted by each source having wavelengths 300nm and 500nm respectively, 
will be : 
(1) 1 : 5 
(2) 1 : 3 
(3) 5 : 3 
(4) 3 : 5 
Solution: (4) 
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 - 2024 (30 Jan Shift 1) 
The work function of a substance is 3.0eV. The longest wavelength of light that can 
cause the emission of photoelectrons from this substance is approximately: 
(1) 215nm 
(2) 414nm 
(3) 400nm 
(4) 200nm 
Solution: (2) 
For P.E.E. :?? =
h?? ?? ?? 
?? =
1240nm - eV
3eV
 
?? = 413.33nm 
?? max
˜ 414nmfor P.E.E. 
 
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 
Solution: (4) 
K.E. = hf -?? 
tan? ?? = h 
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
?? 
Solution: (1) 
1
?? =
13.6z
2
hc
 
1
1
2
-
1
2
2
 … (i) 
1
?? '
=
13.6z
2
hc
 
1
1
2
-
1
3
2
 … (ii) 
On dividing (i) \ & (ii) 
?? '
=
27
32
?? 
Q8 - 2024 (31 Jan Shift 1) 
When a metal surface is illuminated by light of wavelength ?? , the stopping potential is 8V. 
When the same surface is illuminated by light of wavelength 3?? , stopping potential is 2V. 
The threshold wavelength for this surface is : 
(1) 5?? 
(2) 3?? 
(3) 9?? 
(4) 4.5?? 
Solution: (3) 
E = ?? + K
max 
 
?? =
hc
?? 0
 
K
max 
= eV
0
 
8e =
hc
?? -
hc
?? 0
… (i) 
2e =
hc
3?? -
hc
?? 0
… (ii) 
on solving (i) \ & (ii) 
?? 0
= 9?? 
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 
Solution: (3) 
Since 
f
2
< f
0
 
i.e. the incident frequency is less than threshold frequency. Hence there will be no 
emission of photoelectrons. 
? current = 0