WB JEE 2026 | Atoms and Nuclei Question 3 | Physics

WB JEE 2026

MCQ (More than One Correct Answer)

-0.25

A radioactive element ${ }_{92}^{242} \mathrm{X}$ emits two $\alpha$－particles，one electron and two positrons．The transformed nucleus is represented by ${ }_P^{234} Y$ ．The value of $P$ is

WB JEE 2026

MCQ (More than One Correct Answer)

-0.5

The de-Broglie wavelength of an electron in 4th orbit is (where $r=$ radius of the 1st orbit)

$2 \pi r$

$4 \pi r$

$8 \pi r$

$16 \pi r$

WB JEE 2025

MCQ (More than One Correct Answer)

-0

Let the binding energy per nucleon of nucleus is denoted by ' $E_{b n}$ ' and radius of the nucleus is denoted by ' $r$ '. If mass number of nuclei $A$ and $B$ are 64 and 125 respectively, then

$r_A< r_B$

$r_A >r_B$

$E_{b n A} >E_{b n B}$

$E_{b n A}< E_{b n B}$

WB JEE 2023

MCQ (More than One Correct Answer)

-0

A uniform magnetic field B exists in a region. An electron of charge q and mass m moving with velocity v enters the region in a direction perpendicular to the magnetic field. Considering Bohr angular momentum quantization, which of the following statements is/are true?

The radius of n^th orbit $$\mathrm{r_n~\infty ~\sqrt n}$$.

The minimum velocity of the electron is $$\frac{\sqrt{\mathrm{qB} \hbar}}{\mathrm{m}}$$.

Energy of the $$\mathrm{n}^{\text {th }}$$ level $$E_{n} ~\infty~n$$.

Transition frequency $$\omega$$ between two successive levels is independent of n.

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