1
JEE Advanced 2025 Paper 1 Online
MCQ (Single Correct Answer)
+4
-1

List-I shows various functional dependencies of energy $(E)$ on the atomic number $(Z)$. Energies associated with certain phenomena are given in List-II.

Choose the option that describes the correct match between the entries in List-I to those in List-II.

List–I List–II
(P) $E \propto Z^2$ (1) energy of characteristic x-rays
(Q) $E \propto (Z - 1)^2$ (2) electrostatic part of the nuclear binding energy for stable nuclei with mass numbers in the range 30 to 170
(R) $E \propto Z(Z - 1)$ (3) energy of continuous x-rays
(S) $E$ is practically independent of $Z$ (4) average nuclear binding energy per nucleon for stable nuclei with mass number in the range 30 to 170
(5) energy of radiation due to electronic transitions from hydrogen-like atoms
A

P→4, Q→3, R→1, S→2

B

P→5, Q→2, R→1, S→4

C

P→5, Q→1, R→2, S→4

D

P→3, Q→2, R→1, S→5

2
JEE Advanced 2023 Paper 1 Online
MCQ (Single Correct Answer)
+3
-1
List-I shows different radioactive decay processes and List-II provides possible emitted particles. Match each entry in List-I with an appropriate entry from List-II, and choose the correct option.

List - I List - II
(P) ${ }_{92}^{238} U \rightarrow{ }_{91}^{234} \mathrm{~Pa}$ (1) one $\alpha$ particle and one $\beta^{+}$particle
(Q) ${ }_{82}^{214} \mathrm{~Pb} \rightarrow{ }_{82}^{210} \mathrm{~Pb}$ (2) three $\beta^{-}$particles and one $\alpha$ particle
(R) ${ }_{81}^{210} \mathrm{Tl} \rightarrow{ }_{82}^{206} \mathrm{~Pb}$ (3) two $\beta^{-}$particles and one $\alpha$ particle
(S) ${ }_{91}^{228} \mathrm{~Pa} \rightarrow{ }_{88}^{224} \mathrm{Ra}$ (4) one $\alpha$ particle and one $\beta^{-}$particle
(5) one $\alpha$ particle and two $\beta^{+}$particles
A
$P \rightarrow 4, Q \rightarrow 3, R \rightarrow 2, S \rightarrow 1$
B
$P \rightarrow 4, Q \rightarrow 1, R \rightarrow 2, S \rightarrow 5$ 
C
$P \rightarrow 5, Q \rightarrow 3, R \rightarrow 1, S \rightarrow 4$
D
$P \rightarrow 5, Q \rightarrow 1, R \rightarrow 3, S \rightarrow 2$
3
JEE Advanced 2021 Paper 1 Online
MCQ (Single Correct Answer)
+3
-1
A heavy nucleus Q of half-life 20 minutes undergoes alpha-decay with probability of 60% and beta-decay with probability of 40%. Initially, the number of Q nuclei is 1000. The number of alpha-decays of Q in the first one hour is
A
50
B
75
C
350
D
525
4
JEE Advanced 2019 Paper 1 Offline
MCQ (Single Correct Answer)
+3
-1
In a radioactive sample, $${}_{19}^{40}K$$ nuclei either decay into stable $${}_{20}^{40}Ca$$ nuclei with decay constant 4.5 $$ \times $$ 10-10 per year or into stable $${}_{18}^{40}Ar$$ nuclei with decay constant 0.5 $$ \times $$ 10-10 per year. Given that in this sample all the stable $${}_{20}^{40}Ca$$ and $${}_{18}^{40}Ar$$ nuclei are produced by the $${}_{19}^{40}K$$ nuclei only. In time t $$ \times $$ 109 years, if the ratio of the sum of stable $${}_{20}^{40}Ca$$ and $${}_{18}^{40}Ar$$ nuclei to the radioactive $${}_{19}^{40}K$$ nuclei is 99, the value of t will be

[Given : In 10 = 2.3]
A
9.2
B
1.15
C
4.6
D
2.3
JEE Advanced Subjects