1
JEE Main 2022 (Online) 26th July Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

A nucleus of mass $$M$$ at rest splits into two parts having masses $$\frac{M^{\prime}}{3}$$ and $${{2M'} \over 3}(M' < M)$$. The ratio of de Broglie wavelength of two parts will be :

A
1 : 2
B
2 : 1
C
1 : 1
D
2 : 3
2
JEE Main 2022 (Online) 26th July Evening Shift
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
Change Language

Mass numbers of two nuclei are in the ratio of $$4: 3$$. Their nuclear densities will be in the ratio of

A
4 : 3
B
$$\left(\frac{3}{4}\right)^{\frac{1}{3}}$$
C
1 : 1
D
$$\left(\frac{4}{3}\right)^{\frac{1}{3}}$$
3
JEE Main 2022 (Online) 26th July Morning Shift
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
Change Language

The disintegration rate of a certain radioactive sample at any instant is 4250 disintegrations per minute. 10 minutes later, the rate becomes 2250 disintegrations per minute. The approximate decay constant is :

$$\left(\right.$$Take $$\left.\log _{10} 1.88=0.274\right)$$

A
$$0.02 \min ^{-1}$$
B
$$2.7 \min ^{-1}$$
C
$$0.063 \min ^{-1}$$
D
$$6.3 \min ^{-1}$$
4
JEE Main 2022 (Online) 25th July Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Hydrogen atom from excited state comes to the ground state by emitting a photon of wavelength $$\lambda$$. The value of principal quantum number '$$n$$' of the excited state will be : ($$\mathrm{R}:$$ Rydberg constant)

A
$$\sqrt{\frac{\lambda \mathrm{R}}{\lambda-1}}$$
B
$$\sqrt{\frac{\lambda \mathrm{R}}{\lambda \mathrm{R}-1}}$$
C
$$\sqrt{\frac{\lambda}{\lambda \mathrm{R}-1}}$$
D
$$\sqrt{\frac{\lambda R^{2}}{\lambda R-1}}$$
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