1
JEE Main 2019 (Online) 11th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Heat treatment of muscular pain involves radiation of wavelength of about 900 nm. Which spectral line of H atom is suitable for this purpose?

[RH = 1 $$ \times $$ 105 cm–1, h = 6.6 $$ \times $$ 10–34 Js, c = 3 $$ \times $$ 108 ms–1]
A
Balmer, $$\infty $$ $$ \to $$ 2
B
Paschen, 5 $$ \to $$ 3
C
Paschen, $$\infty $$ $$ \to $$ 3
D
Lyman, $$\infty $$ $$ \to $$ 1
2
JEE Main 2019 (Online) 10th January Evening Slot
MCQ (Single Correct Answer)
+4
-1
The ground state energy of hydrogen atom is – 13.6 eV. The energy of second excited state of He+ ion in eV is :
A
$$-$$ 6.04
B
$$-$$ 54.4
C
$$-$$ 27.2
D
$$-$$ 3.4
3
JEE Main 2019 (Online) 9th January Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
Which of the following combination of statements is true regarding the interpretation of the atomic orbitals ?

(a) An electron in an orbital of high angular momentum stays away from the nucleus than an electron in the orbital of lower angular momentum.

(b) For a given value of the principal quantum number, the size of the orbit is inversely proportional to the azimuthal quantum number.

(c) According to wave mechanics, the ground state angular momentum is equal to $${h \over {2\pi }}$$.

(d) The plot of $$\psi $$ vs r for various azimuthal quantum numbers, shows peak shifting towards higher r value.
A
(a), (b)
B
(a), (d)
C
(b), (c)
D
(a), (c)
4
JEE Main 2019 (Online) 9th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
The highest value of the calculated spin- only magnetic moment (in BM) among all the transition metal complexes is :
A
5.92
B
6.93
C
3.87
D
4.90
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