1
COMEDK 2023 Morning Shift
MCQ (Single Correct Answer)
+1
-0

The wavelength of the first line of Lyman series for $$\mathrm{H}$$ - atom is equal to that of the second line of Balmer series for a $$\mathrm{H}$$-like ion. The atomic number $$\mathrm{Z}$$ of $$\mathrm{H}$$-like ion is

A
4
B
1
C
2
D
3
2
COMEDK 2023 Morning Shift
MCQ (Single Correct Answer)
+1
-0

The first emission of hydrogen atomic spectrum in Lyman series appears at a wavelength of

A
$$\frac{3 R}{4} \mathrm{~cm}^{-1}$$
B
$$\frac{4}{3 R} \mathrm{~cm}$$
C
$$\frac{7 R}{144} \mathrm{~cm}^{-1}$$
D
$$\frac{400}{9 R} \mathrm{~cm}$$
3
COMEDK 2023 Evening Shift
MCQ (Single Correct Answer)
+1
-0

The mass number of two nuclei $$\mathrm{P}$$ and $$\mathrm{Q}$$ are 27 and 125 respectively. The ratio of their radii $$R_P: R_Q$$ is given by:

A
9 : 25
B
3 : 5
C
27 : 25
D
5 : 3
4
COMEDK 2023 Evening Shift
MCQ (Single Correct Answer)
+1
-0

In a nuclear reaction 2 deuteron nuclei combine to form a helium nucleus. The energy released in $$\mathrm{MeV}$$ will be: (Given mass of deuteron $$=2.01355 \mathrm{~amu}$$. and mass of helium nucleus $$=4.0028 \mathrm{~amu}$$.

A
24.3 MeV
B
2.262 MeV
C
22.62 MeV
D
0.0243 MeV
COMEDK 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