WB JEE 2021 | Atoms and Nuclei Question 10 | Physics

WB JEE 2021

MCQ (Single Correct Answer)

-0.25

Let r, v, E be the radius of orbit, speed of electron and total energy of electron respectively in H-atom. Which of the following quantities according to Bohr theory, is proportional to the quantum number n ?

$${r \over E}$$

$${r \over v}$$

WB JEE 2020

MCQ (Single Correct Answer)

-0.25

If R is the Rydberg constant in cm^-1, then hydrogen atom does not emit any radiation of wavelength in the range of

$${1 \over R}$$ to $${4 \over {3R}}$$ cm

$${7 \over 5R}$$ to $${19 \over {5R}}$$ cm

$${4 \over R}$$ to $${36 \over {5R}}$$ cm

$${9 \over R}$$ to $${144 \over {7R}}$$ cm

WB JEE 2020

MCQ (Single Correct Answer)

-0.25

A nucleus X emits a $$\beta $$-particle to produce a nucleus Y. If their atomic masses are M_x and M_y respectively, then the maximum energy of the $$\beta $$-particle emitted is (where, m_e is the mass of an electron and c is the velocity of light)

$$({M_x} - {M_y} - {m_e}){c^2}$$

$$({M_x} - {M_y} + {m_e}){c^2}$$

$$({M_x} - {M_y} ){c^2}$$

$$({M_x} - {M_y} - {2m_e}){c^2}$$

WB JEE 2020

MCQ (Single Correct Answer)

-0.25

For nuclei with mass number close to 119 and 238, the binding energies per nucleon are approximately 7.6 MeV and 8.6 MeV, respectively. If a nucleus of mass number 238 breaks into two nuclei of nearly equal masses, what will be the approximate amount of energy released in the process of fission?

214 MeV

119 MeV

2047 MeV

1142 MeV

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