If the velocity of an electron in Bohr’s first orbit is 3.19 x 10⁶ ms^-1, then the de Broglie wavelength associated with it would be:

1. 314 pm
2.456pm
3. 228pm
4.560nm

According to the Bohr Theory, which of the following transitions in the hydrogen atom will give rise to the least energetic photon?
1. n = 5 to n = 3
2. n = 6 to n = 1
3. n = 5 to n = 4
4. n = 6 to n = 5

Match the ensuing rules with the corresponding statements:
 

Which of the following options does not represent ground state electronic configuration of an atom?

1. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}3{\mathrm{d}}^{8}4{\mathrm{s}}^2$

2. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}3{\mathrm{d}}^{9}4{\mathrm{s}}^2$

3. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}3{\mathrm{d}}^{10}4{\mathrm{s}}^1$

4. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}3{\mathrm{d}}^{5}4{\mathrm{s}}^1$

If the energy value is E = 3.03 × 10^–19 Joules, (h = 6.6×10^–34 J x sec., C = 3×10⁸ m/sec), then the value of the corresponding wavelength is:

Uncertainty in position of a $e^{-}$ and He is similar. If uncertainty in momentum of $e^{-}$ is $\mathrm{32<mspace\; width="1em"></mspace>}\times {10}^5$, then uncertainty in momentum of He will be:

Which of the following nuclei contains the maximum number of neutrons?
1. \(_8^{16}\mathrm{O}\)
2. \(_{12}^{24}\mathrm{Mg}\)
3.\(_{26}^{56}\mathrm{Fe}\)
4. \(_{38}^{88}\mathrm{Sr}\)

The wavelength of yellow light emitted by a sodium lamp is 580 nm. Calculate its frequency and wave number, respectively.

1. 517 × 10¹⁴ s^–1 , 172 × 10⁶ m^–1

2. 6.17 × 10¹⁴ s^–1 , 1.72 × 10⁶ m^–1

3. 4.17 × 10¹⁴ s^–1 , 2.72 × 10⁶ m^–1

4. 5.17 × 10¹⁴ s^–1 , 1.72 × 10⁶ m^–1

Calculate the energy of a photon having a frequency of 3 × 10¹⁵ Hz. 

1. 1.988 × ${10}^{-18}$ J
2. 1.588 × ${10}^{-18}$ J
3. 1.288 × ${10}^{-18}$ J
4. 2.988 × ${10}^{-18}$ J