Light is a kind of wave. The wavelength of visible light ranges from about 4000 $\stackrel{\circ }{A}$ to 7000 $\stackrel{\circ }{A}$. Which of the following statements is false?

1. Ultraviolet light has a wavelength shorter than 4000 $\stackrel{\circ }{A}$

2. Infrared light has a wavelength longer than 7000 $\stackrel{\circ }{A}$

3. Red light has wavelength near about 7000 $\stackrel{\circ }{A}$

4. Violet light has wavelength near about 7000 $\stackrel{\circ }{A}$.

Concept Questions :-

Spectral series
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

An $\alpha -$particle of energy 5 MeV is scattered through $180°$ by a fixed uranium nucleus. The distance of closest approach is of the order

(1)            (2)             (3)              (4)

Concept Questions :-

Various atomic model
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Out of the following which one is not a possible energy for a photon to be emitted by hydrogen atom according to Bohr's atomic model:

(1) 13.6 eV             (2) 0.65 eV              (3) 1.9 eV              (4) 11.1 eV

Concept Questions :-

Bohr's model of atom
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Energy of an electron in an excited hydrogen atom is -3.4 eV. Its angular momentum will be (h = 6.626 $×$ 10-34 J-s)

1. 1.11 $×$ 1034 J s                   2. 1.51 $×$10-31 J s

3. 2.11 $×$ 10-34 J s                  4. 3.72 $×$ 10-34 J s

Concept Questions :-

Bohr's model of atom
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

As per Bohr model, the minimum energy (in eV) required to remove the electron from the ground state of double ionized lithium (Z=3) is

(1) 1.51        (2) 13.6            (3) 40.8        (4) 122.4

Concept Questions :-

Bohr's model of atom
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The wavelength of Ka X-rays produced by an X-ray tube is 0.76 $\stackrel{\circ }{A}$. Find the atomic number of the anode material of the tube?

1. 41                                    2. 30

3. 20                                    4. 10

Concept Questions :-

X-ray
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

According to Bohr's theory the moment of momentum of an electron revolving in second orbit of hydrogen atom will be [MP PET 1999; KCET 2003; VITEEE 2006]

(1) 2$\mathrm{\pi h}$        (2) $\mathrm{\pi h}$         (3) $\frac{h}{\mathrm{\pi }}$          (4) $\frac{2h}{\mathrm{\pi }}$

Concept Questions :-

Bohr's model of atom
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The ionisation energy of hydrogen atom is 13.6 eV. Following Bohr's theory, the energy corresponging to a transition between 3rd and 4th orbit is   [1992]

(1) 3.40 eV        (2) 1.51 eV        (3) 0.85        (4) 0.66 eV

Concept Questions :-

Bohr's model of atom
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The K$\propto$ line obtained for molybdenum (Z = 42) target is 0.71 $\stackrel{\circ }{A}$. Then, the wavelength of the ${K}_{\alpha }$ line of copper (Z = 29) is:

(A) 2.14 $\stackrel{\circ }{A}$                               (B) 1.52 $\stackrel{\circ }{A}$

(C) 1.04 $\stackrel{\circ }{A}$                               (D) 0.71 $\stackrel{\circ }{A}$

Concept Questions :-

Spectral series
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The ratio of the energies of the hydrogen atom in its first to second excited states is

(1) $\frac{1}{4}$       (2) $\frac{4}{9}$          (3) $\frac{9}{4}$            (4) 4

Concept Questions :-

Bohr's model of atom