Problem 47
What is the trend of energy of Bohr's orbits? (a) Energy of the orbit increases as we move away from the nucleus. (b) Energy of the orbit decreases as we move away from the nucleus. (c) Energy remains same as we move away from the nucleus. (d) Energy of Bohr's orbit cannot be calculated.
Problem 49
What is the velocity of electron present in first Bohr orbit of hydrogen atom? (a) \(2.18 \times 10^{5} \mathrm{~m} / \mathrm{s}\) (b) \(2.18 \times 10^{6} \mathrm{~m} / \mathrm{s}\) (c) \(2.18 \times 10^{-18} \mathrm{~m} / \mathrm{s}\) (d) \(2.18 \times 10^{-9} \mathrm{~m} / \mathrm{s}\)
Problem 52
Splitting of spectral lines under the influence of magnetic field is called (a) Stark effect (b) Zeeman effect (c) photoelectric effect (d) screening effect.
Problem 53
The de Broglie wavelength associated with a ball of mass \(200 \mathrm{~g}\) and moving at a speed of 5 metres/hour, is of the order of \(\left(h=6.625 \times 10^{-34} \mathrm{~J} \mathrm{~s}\right)\) is (a) \(10^{-15} \mathrm{~m}\) (b) \(10^{-20} \mathrm{~m}\) (c) \(\mathrm{r} 0^{-25} \mathrm{~m}\) (d) \(10^{-30} \mathrm{~m}\)
Problem 55
The wavelength of an electron moving with velocity of \(10^{7} \mathrm{~m} \mathrm{~s}^{-1}\) is (a) \(7.27 \times 10^{-11} \mathrm{~m}\) (b) \(3.55 \times 10^{-11} \mathrm{~m}\) (c) \(8.25 \times 10^{-4} \mathrm{~m}\) (d) \(1.05 \times 10^{-16} \mathrm{~m}\)
Problem 56
What will be the wavelength of an electron moving with \(\frac{1}{10}\) th of velocity of light? (a) \(2.43 \times 10^{-11} \mathrm{~m}\) (b) \(243 \times 10^{-11} \mathrm{~m}\) (c) \(0.243 \mathrm{~m}\) (d) \(2.43 \times 10^{-4} \mathrm{~m}\)
Problem 57
If the velocity of an electron in Bohr's first orbit is \(2.19 \times 10^{6} \mathrm{~m} \mathrm{~s}^{-1}\), what will be the de Broglie wavelength associated with it? (a) \(2.19 \times 10^{-6} \mathrm{~m}\) (b) \(4.38 \times 10^{-6} \mathrm{~m}\) (c) \(3.32 \times 10^{-10} \mathrm{~m}\) (d) \(3.32 \times 10^{10} \mathrm{~m}\)
Problem 62
What will be the uncertainty in velocity of an electron when the uncertainty in its position is \(1000 \AA\) ? (a) \(5.79 \times 10^{2} \mathrm{~m} \mathrm{~s}^{-1}\) (b) \(5.79 \times 10^{8} \mathrm{~m} \mathrm{~s}^{-1}\) (c) \(5.79 \times 10^{4} \mathrm{~m} \mathrm{~s}^{-1}\) (d) \(5.79 \times 10^{-10} \mathrm{~m} \mathrm{~s}^{-1}\)
Problem 63
The region where probability density function reduces to zero is called (a) probability density region (b) nodal surfaces (c) orientation surfaces (d) wave function.
Problem 64
Theprobability of finding out an electron at a point within an atom is proportional to the (a) square of the orbital wave function \(i . e, \psi^{2}\) (b) orbital wave function \(i . e, \psi\) (c) Hamiltonian operator i.e., \(H\) (d) principal quantum number i.e., \(n\)
