1
JEE Main 2019 (Online) 11th January Evening Slot
MCQ (Single Correct Answer)
+4
-1
The de Broglie wavelength ($$\lambda $$) associated with a photoelectron varies with the frequency (v) of the incident radiation as, [v0 is threshold frequency] :
A
$$\lambda \,\infty \,{1 \over {{{\left( {v - {v_0}} \right)}^{{3 \over 2}}}}}$$
B
$$\lambda \,\infty \,{1 \over {{{\left( {v - {v_0}} \right)}^{{1 \over 4}}}}}$$
C
$$\lambda \,\infty \,{1 \over {\left( {v - {v_0}} \right)}}$$
D
$$\lambda \,\infty \,{1 \over {{{\left( {v - {v_0}} \right)}^{{1 \over 2}}}}}$$
2
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
3
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
4
JEE Main 2019 (Online) 10th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Which of the graphs shown below does not represent the relationship between incident light and the electron ejected from metal surface ?
A
JEE Main 2019 (Online) 10th January Morning Slot Chemistry - Structure of Atom Question 121 English Option 1
B
JEE Main 2019 (Online) 10th January Morning Slot Chemistry - Structure of Atom Question 121 English Option 2
C
JEE Main 2019 (Online) 10th January Morning Slot Chemistry - Structure of Atom Question 121 English Option 3
D
JEE Main 2019 (Online) 10th January Morning Slot Chemistry - Structure of Atom Question 121 English Option 4
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