1
NEET 2017
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
Radioactive material 'A' has decay constant '8 $$\lambda $$' and material 'B' has decay constant '$$\lambda $$'. Initially they have same number of nuclei. After what time, the ratio of number of nuclei of material 'B' to that 'A' will be e ?
A
$${1 \over {7\lambda }}$$
B
$${1 \over {8\lambda }}$$
C
$${1 \over {9\lambda }}$$
D
$${1 \over {\lambda }}$$
2
NEET 2016 Phase 2
MCQ (Single Correct Answer)
+4
-1
If an electron in a hydrogen atom jumps from the 3rd orbit to the 2nd orbit, it emits a photon of wavelength $$\lambda $$. When it jumps from the 4th orbit to the 3rd orbit, the corresponding wavelength of the photon will be
A
$${{16} \over {25}}\lambda $$
B
$${9 \over {16}}\lambda $$
C
$${{20} \over 7}\lambda $$
D
$${{20} \over {13}}\lambda $$
3
NEET 2016 Phase 2
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
The half-life of a radioactive substance is 30 minutes. The time (in minutes) taken between 40% decay and 85% decay of the same radioactive substance is
A
15
B
30
C
45
D
60
4
NEET 2016 Phase 1
MCQ (Single Correct Answer)
+4
-1
When an $$\alpha $$-particle of mass m moving with velocity v bombards on a heavy nucleus of charge Ze, its distance of closest approach from the nucleus depends on m as
A
$${1 \over {{m^2}}}$$
B
m
C
$${1 \over m}$$
D
$${1 \over {\sqrt m }}$$
NEET Subjects
EXAM MAP
Medical
NEET
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
CBSE
Class 12