1
WB JEE 2022
MCQ (Single Correct Answer)
+1
-0.25

In Bohr model of atom, radius of hydrogen atom in ground state is r1 and radius of He+ ion in ground state is r2. Which of the following is correct?

A
$${{{r_1}} \over {{r_2}}} = 4$$
B
$${{{r_1}} \over {{r_2}}} = {1 \over 2}$$
C
$${{{r_1}} \over {{r_2}}} = {1 \over 4}$$
D
$${{{r_2}} \over {{r_1}}} = {1 \over 2}$$
2
WB JEE 2022
MCQ (Single Correct Answer)
+1
-0.25

Which one of the following is the correct set of four quantum numbers (n, 1, m, s) ?

A
$$\left( {3,0, - 1, + {1 \over 2}} \right)$$
B
$$\left( {4,3, - 2, - {1 \over 2}} \right)$$
C
$$\left( {3,1, - 2, - {1 \over 2}} \right)$$
D
$$\left( {4,2, - 3, + {1 \over 2}} \right)$$
3
WB JEE 2021
MCQ (Single Correct Answer)
+2
-0.5
The atomic masses of helium and neon are 4.0 and 20.0 amu respectively. The value of the de-Broglie wavelength of helium gas at $$-$$73$$^\circ$$C is M times the de-Broglie wavelength of neon at 727$$^\circ$$C. The value of M is
A
5
B
25
C
$${1 \over {5}}$$
D
$${1 \over {25}}$$
4
WB JEE 2020
MCQ (Single Correct Answer)
+1
-0.25
The maximum number of electrons in an atom in which the last electron filled has the quantum numbers n = 3, l = 2 and m = $$ - $$ 1 is
A
17
B
27
C
28
D
30
WB JEE Subjects