The ionisation potential of H-atom is -13.6 eV. Photons with an energy of 12.85 eV are incident on a sample of H-atoms in their ground state. How many spectral lines are expected in emitted radiation?
1. 2
2. 6
3. 4
4. 1
Let f1 be the maximum frequency of the Lyman series, f2 be the frequency of the first line of the Lyman series, and f3 be the frequency of the series limit of the Balmer series, then which of the following is correct?
1. - =
2. - =
3. + =
4. 2 = +
What happens when an electron in a hydrogen-like atom jumps from a lower energy level to a higher energy level?
1. | kinetic energy increases. |
2. | angular momentum decreases. |
3. | de-Broglie wavelength associated with electron increases. |
4. | angular momentum remains constant. |
If the wavelength of the first line in the Balmer Series of the hydrogen spectrum is λ, then what is the wavelength of the second line in this series?
1.
2.
3.
4.
In the Bohr model of the hydrogen atom, the force on the electron depends on the principal quantum number "n" as:
1. | \(F \propto \frac{1}{n^3}\) |
2. | \(F \propto \frac{1}{n^4}\) |
3. | \(F \propto \frac{1}{n^5}\) |
4. | It does not depend on n. |
E1, E2 and E3 are energies of an electron in three consecutive energy levels of a hydrogen-like atom, such that E1<E2<E3. The wavelength emitted in the transition from E3 to E2 is λ2 and the wavelength emitted in the transition from E2 to E1 is λ1. The wavelength emitted in transition from E3 to E1 is:
1.
2.
3.
4.
In an atom, if the transition from n = 4 to n = 3 gives ultraviolet radiation, then to obtain infrared radiation, the transition should be:
1. | 5 → 4 | 2. | 3 → 2 |
3. | 2 → 1 | 4. | 3 → 1 |
Which other physical quantity, like angular momentum, is quantized in Bohr's model of a hydrogen atom?
1. Kinetic energy
2. Magnetic moment
3. Potential energy
4. Mechanical energy
Let R represent the orbital radius of an electron moving in an orbit and K represent its kinetic energy. Then the quantity KR varies with principal quantum number n as:
1. | 2. | ||
3. | 4. |
In an -particle scattering experiment, the number of particles scattered per minute in a direction perpendicular to the direction of incident particles is 40. What will be the number of particles scattered at an angle of 60° per minute?
1. | 145 | 2. | 160 |
3. | 172 | 4. | 157 |