1
JEE Main 2017 (Online) 8th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
Two deuterons undergo nuclear fusion to form a Helium nucleus. Energy released in this process is : (given binding energy per nucleon for deuteron = 1.1 MeV and for helium = 7.0 MeV)
A
30.2 MeV
B
32.4 MeV
C
23.6 MeV
D
25.8 MeV
2
JEE Main 2017 (Online) 8th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
According to Bohr’s theory, the time averaged magnetic field at the centre (i.e. nucleus) of a hydrogen atom due to the motion of electrons in the nth orbit is proportional to : (n = principal quantum number)
A
$${n^{ - 4}}$$
B
$${n^{ - 5}}$$
C
n$$-$$3
D
n$$-$$2
3
JEE Main 2017 (Offline)
MCQ (Single Correct Answer)
+4
-1
Change Language
Some energy levels of a molecule are shown in the figure. The ratio of the wavelengths r = $${{\lambda _1}}$$/$${{\lambda _2}}$$, is given by:

JEE Main 2017 (Offline) Physics - Atoms and Nuclei Question 205 English
A
r = 1/3
B
r = 4/3
C
r = 2/3
D
r = 3/4
4
JEE Main 2017 (Offline)
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
Change Language
A radioactive nucleus A with a half life T, decays into a nucleus B. At t = 0, there is no nucleus B. At sometime t, the ratio of the number of B to that of A is 0.3. Then, t is given by :
A
$$t = {T \over {\log (1.3)}}$$
B
$$t = T\log (1.3)$$
C
$$t = {T \over 2}{{\log 2} \over {\log 1.3}}$$
D
$$t = T{{\log 1.3} \over {\log 2}}$$
JEE Main Subjects
EXAM MAP
Medical
NEETAIIMS
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
Staff Selection Commission
SSC CGL Tier I
CBSE
Class 12