1
JEE Main 2023 (Online) 12th April Morning Shift
Numerical
+4
-1

A common example of alpha decay is $${ }_{92}^{238} \mathrm{U} \longrightarrow{ }_{90}^{234} \mathrm{Th}+{ }_{2} \mathrm{He}^{4}+\mathrm{Q}$$

Given :

$${ }_{92}^{238} \mathrm{U}=238.05060 ~\mathrm{u}$$,

$${ }_{90}^{234} \mathrm{Th}=234.04360 ~\mathrm{u}$$,

$${ }_{2}^{4} \mathrm{He}=4.00260 ~\mathrm{u}$$ and

$$1 \mathrm{u}=931.5 \frac{\mathrm{MeV}}{c^{2}}$$

The energy released $$(Q)$$ during the alpha decay of $${ }_{92}^{238} \mathrm{U}$$ is __________ MeV

2
JEE Main 2023 (Online) 11th April Evening Shift
Numerical
+4
-1

A nucleus disintegrates into two nuclear parts, in such a way that ratio of their nuclear sizes is $$1: 2^{1 / 3}$$. Their respective speed have a ratio of $$n: 1$$. The value of $n$ is __________.

3
JEE Main 2023 (Online) 10th April Evening Shift
Numerical
+4
-1

If 917 $$\mathop A\limits^o$$ be the lowest wavelength of Lyman series then the lowest wavelength of Balmer series will be ___________ $$\mathop A\limits^o$$.

4
JEE Main 2023 (Online) 10th April Morning Shift
Numerical
+4
-1
Out of Syllabus

The decay constant for a radioactive nuclide is 1.5 $$\times$$ 10$$^{-5}$$ s$$^{-1}$$. Atomic weight of the substance is 60 g mole$$^{-1}$$, ($$N_A=6\times10^{23}$$). The activity of 1.0 $$\mu$$g of the substance is ___________ $$\times$$ 10$$^{10}$$ Bq.