1
JEE Main 2020 (Online) 6th September Morning Slot
+4
-1
You are given that Mass of $${}_3^7Li$$ = 7.0160u,
Mass of $${}_2^4He$$ = 4.0026u
and Mass of $${}_1^1H$$ = 1.0079u.
When 20 g of $${}_3^7Li$$ is converted into $${}_2^4He$$ by proton capture, the energy liberated, (in kWh), is :
[Mass of nucleon = 1 GeV/c2]
A
6.82 $$\times$$ 105
B
4.5 $$\times$$ 105
C
8 $$\times$$ 106
D
1.33 $$\times$$ 106
2
JEE Main 2020 (Online) 5th September Evening Slot
+4
-1
Out of Syllabus
A radioactive nucleus decays by two different processes. The half life for the first process is 10 s and that for the second is 100 s. The effective half life of the nucleus is close to :
A
12 sec
B
9 sec
C
55 sec
D
6 sec
3
JEE Main 2020 (Online) 5th September Morning Slot
+4
-1
Out of Syllabus
Activities of three radioactive substances A, B and C are represented by the curves A, B and C, in the figure. Then their half-lives
$${T_{{1 \over 2}}}\left( A \right)$$ : $${T_{{1 \over 2}}}\left( B \right)$$ : $${T_{{1 \over 2}}}\left( C \right)$$ are in the ratio :
A
3 : 2 : 1
B
2 : 1 : 1
C
4 : 3 : 1
D
2 : 1 : 3
4
JEE Main 2020 (Online) 4th September Evening Slot
+4
-1
Find the Binding energy per neucleon for $${}_{50}^{120}Sn$$. Mass of proton mp = 1.00783 U, mass of neutron mn = 1.00867 U and mass of tin nucleus mSn = 119.902199 U. (take 1U = 931 MeV)
A
9.0 MeV
B
8.5 MeV
C
8.0 MeV
D
7.5 MeV
EXAM MAP
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