1
JEE Main 2018 (Online) 15th April Morning Slot
+4
-1
Ejection of the photoelectron from metal in the photoelectric experiment can be stopped by applying 0.5 V when the radiation of 250 nm is used. The work function of the metal is :
A
4 eV
B
4.5 eV
C
5 eV
D
5.5 eV
2
JEE Main 2017 (Online) 9th April Morning Slot
+4
-1
The electron in the hydrogen atom undergoes transition from higher orbitals to orbital of radius 211.6 pm. This transition is associated with :
A
Lyman series
B
Balmer series
C
Paschen series
D
Brackett series
3
JEE Main 2017 (Online) 8th April Morning Slot
+4
-1
If the shortest wavelength in Lyman series of hydrogen atom is A, then the longestwavelength in Paschen series of He+ is :
A
$${{5A} \over 9}$$
B
$${{9A} \over 5}$$
C
$${{36A} \over 5}$$
D
$${{36A} \over 7}$$
4
JEE Main 2017 (Offline)
+4
-1
The radius of the second Bohr orbit for hydrogen atom is:
(Planck’s Const. h = 6.6262 × 10-34 Js; mass of electron = 9.1091 × 10-31 kg; charge of electron (e) = 1.60210 × 10-19 C; permittivity of vacuum ($${\varepsilon _0}$$) = 8.854185 × 10-12 kg-1 m-3 A2)
A
4.76 $$\mathop {\rm A}\limits^o$$
B
2.12 $$\mathop {\rm A}\limits^o$$
C
0.529 $$\mathop {\rm A}\limits^o$$
D
1.65 $$\mathop {\rm A}\limits^o$$
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