1

### IIT-JEE 2005

Subjective
Find the velocity (ms-1) of electron in first Bohr's orbit of radius a0. Also find the de Broglie's wavelength (in m). Find the orbital angular momentum of 2p orbital of hydrogen atom in units of $h/2 \pi$.

3.34 $\times$ 10-10 m, $\sqrt 2 {h \over {2\pi }}$
2

### IIT-JEE 2004

Subjective
A ball of mass 100 g is moving with 100 ms-1. Find it's wavelength.

6.627 $\times$ 10-35 m
3

### IIT-JEE 2004

Subjective
The Schrodinger wave equation for hydrogen atom is

$$\psi = {1 \over {4\sqrt {2\pi } }}{\left( {{1 \over {{a_0}}}} \right)^{3/2}}\left( {2 - {{{r_0}} \over {{a_0}}}} \right){e^{ - {r_0}/{a_0}}}$$
Where a0 is Bohr's radius. If the radial node in 2s be at r0, then find r0 in terms of a0.

2a0
4

### IIT-JEE 2003

Subjective
Wavelength of high energy transition of H-atoms is 91.2 nm. Calculate the corresponding wavelength of He atoms.

22.8 nm