# Atoms and Nuclei · Physics · COMEDK

Start Practice## MCQ (Single Correct Answer)

COMEDK 2024 Evening Shift

The binding energy per nucleon for $$\mathrm{C}^{12}$$ is $$7.68 \mathrm{~MeV}$$ and that for $$\mathrm{C}^{13}$$ is $$7.47 \mathrm{~MeV}$$. The energ...

COMEDK 2024 Evening Shift

The distance of closest approach when an alpha particle of kinetic energy $$6.5 \mathrm{~MeV}$$ strikes a nucleus of atomic number 50 is

COMEDK 2024 Evening Shift

If an electron in a hydrogen atom jumps from the third orbit to the second orbit, it emits a photon of wavelength $$\lambda$$. When it jumps from the ...

COMEDK 2024 Evening Shift

An electron has a mass of $$9.1 \times 10^{-31} \mathrm{~kg}$$. It revolves round the nucleus in a circular orbit of radius $$0.529 \times 10^{-10} \m...

COMEDK 2024 Evening Shift

$$
\text { If the nuclear radius of }{ }^{27} \mathrm{Al} \text { is } 3.6 \text { fermi, the nuclear radius of }{ }^{125} \mathrm{Fe} \text { is }
$$...

COMEDK 2024 Morning Shift

The ratio of the radii of the nucleus of two element $$\mathrm{X}$$ and $$\mathrm{Y}$$ having the mass numbers 232 and 29 is:

COMEDK 2024 Morning Shift

The closest approach of an alpha particle when it make a head on collision with a gold nucleus is $$10 \times 10^{-14} \mathrm{~m}$$, then the kinetic...

COMEDK 2024 Morning Shift

Find the binding energy of the tritium nucleus:
[Given: mass of $$1 \mathrm{H}^3=3.01605 \mathrm{~u} ; \mathrm{~m}_{\mathrm{p}}=1.00782 \mathrm{~u} ; ...

COMEDK 2023 Morning Shift

The mass density of a nucleus varies with mass number $$A$$ as

COMEDK 2023 Morning Shift

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 $$\mathrm{H}$$-l...

COMEDK 2023 Morning Shift

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

COMEDK 2023 Evening Shift

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:

COMEDK 2023 Evening Shift

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 $$=...

COMEDK 2023 Evening Shift

A particle at rest decays in to two particles of mass $$m_1$$ and $$m_2$$ and move with velocities $$v_1$$ and $$v_2$$. The ratio of their de Broglie ...

COMEDK 2023 Evening Shift

The ground state energy of hydrogen atom is $$-13.6 \mathrm{~eV}$$. If the electron jumps from the $$3^{\text {rd }}$$ excited state to the ground sta...

COMEDK 2023 Evening Shift

In the head-on collision of two alpha particles $$\alpha_1$$ and $$\alpha_2$$ with the gold nucleus, the closest approaches are 31.4 fermi and 94.2 fe...

COMEDK 2023 Evening Shift

Which of the following statement is true when a gamma decay occurs from the nucleus of an atom?

COMEDK 2022

During $$\alpha$$-decay, atomic mass of parent nuclei is

COMEDK 2022

Which of the following series spectrum of hydrogen atom lies in ultraviolet region?

COMEDK 2022

The wavelength of the second line of Balmer series is 486.4 nm. What is the wavelength of the first line of Lyman series?

COMEDK 2021

The Lyman series of a hydrogen atom belongs
in which category

COMEDK 2021

If an electron in hydrogen atom jumps from an orbit of level $$n=3$$ to an orbit at level $$n=2$$, emitted radiation has a frequency of
(R = Rydberg's...

COMEDK 2021

Ba-122 has half-life of 2 min. Experiment has to be done using Ba-122 and it takes 10 min to set up the experiment. It initially 80 g at Ba-122 was ta...

COMEDK 2021

When the speed of light becomes $$\frac{2}{3}$$ of its present value, then the energy released in a given atomic explosion would

COMEDK 2020

An electron of an atom transits from $$n_1$$ to $$n_2$$. In which of the following maximum frequency of photon will be emitted?

COMEDK 2020

Two protons are kept at a separation of 40 $$\mathop A\limits^o $$. F$$_n$$ is the nuclear force and F$$_e$$ is the electrostatic force between them. ...

COMEDK 2020

Two radioactive materials X$$_1$$ and X$$_2$$ have decay constant 5$$\lambda$$ and $$\lambda$$, respectively. If initially they have the same number o...