Spectrum

1. There will be total 20  MCQ in this test.
2. Please keep a pen and paper ready for rough work but keep your books away.
3. The test will consist of only objective type multiple choice questions requiring students to mouse-click their correct choice of the options against the related question number.
4. No negative marking for incorrect choice.
5. Please click on “Finish the Test” when you want to exit.
6. All the best – Happy Studying.

1. For Balmer series,the initial state n₁ is :

4

2

3

1

Question 1 of 20

2. Calculate the wavelength of light that corresponds to the radiation that is given off during the transition of an electron from the n = 5 to n = 2 state of the hydrogen atom.

434 nm

275 nm

305 nm

183 nm

Question 2 of 20

3. Which of the following subatomic particles is responsible for the spectrum of radiation emitted by an element or compound?

neutron

electron

proton

photon

Question 3 of 20

4. The total energy of an electron in the n^th orbit of a hydrogen atom is given by the formula
E_n = -13.6 eV/n². What does the negative energy for an electron indicate?

Energy of electron in an atom is lower than energy of an electron far away from nucleus

The electron has a negative charge.

The electron is far away from nucleus

Electrons have both wave and particle-like properties.

Question 4 of 20

5. Which of the following is not true about Bohr's model of the atom?

Electrons behave like waves and particles simultaneously.

Electrons revolve in discrete, quantized orbits only.

mvr = nh/ 2π

Atoms radiate discrete Electromagnetic energies only.

Question 5 of 20

6. In the absorption spectrum, the wavelengths which are absorbed, are missing and they appear as:

Bright lines

Light bands

Bright bands

Dark lines

Question 6 of 20

7. Many home bathrooms have infrared light fixtures to help warm the room, and this light is not cancer causing. Which of the following quality make it so useful?

The amplitudes of these waves are short

The energy of IR light is greater.

The temperature of the IR light.

The wavelength of IR rays is longer.

Question 7 of 20

8. By use of a suitable filter, the green mercury emission line can be isolated. This line has a wavelength of 546.1 nm. What is the frequency? [1 Hz = 1 s^-1]

1.820 x 10⁴ Hz

5.461 x 10^-7 Hz

1.820 x 10^-13 Hz

0.0054 x 10¹⁷ Hz

Question 8 of 20

9. An electron falls from one energy level to another; it releases a certain amount of light with a frequency of 5.100 x 10¹⁴ Hz. What energy is associated with this electron?

1.3 13x 10²² J

3.379 x 10^-19 kJ

33.8 x 10^-20 J

1.79 0x 10^-1kJ

Question 9 of 20

10. The energy associated with the transition of an electron from the n=1 state to the n=3 state of H atoms is:

+1.74 x 10^-17 Joules.

-1.94 x 10^-18 Joules.

+1.94 x 10^-18 Joules.

-1.74 x 10^-17 Joules.

Question 10 of 20

11. For Paschen series, the initial state n₁ is :

2

4

3

1

Question 11 of 20

12. Zeeman effect is the splitting of spectral line in presence of:

electricity

magnetic effect

molecule

electric field

Question 12 of 20

13. EM spectrum shows all forms of radiation except one of the followings:

X-rays

Infra red

Gamma Rays

Beta rays

Question 13 of 20

14. It takes 495.8 kJ/mol of energy to ionize sodium. What frequency (s-1) and wavelength (nm) of light would be required to ionize sodium?

A

B

C

D

Question 14 of 20

15. Which of the following is not a type of electromagnetic radiation?

x-rays

sound waves

ultraviolet radiation

red light

Question 15 of 20

16. How much energy is needed to ionize a hydrogen atom if electron is present in n=1 orbit?

13.6 eV

10.2 eV

3.4eV

1 eV

Question 16 of 20

17. Which of the following spectral series of line spectrum of hydrogen atom belongs to the ultra violet region?

Lyman

Brackett

Balmer

Paschen

Question 17 of 20

18. A Na lamp emits yellow light with a wavelength of 589 nm. What is the energy of a single photon in this light?

5.09 x 10¹⁵ Joules.

3.37 x 10^-19 Joules.

5.09 x 10¹⁴ Joules.

1.12 x 10^-25 Joules.

Question 18 of 20

19. Splitting of spectral line in presence of electric field is called:

Zeeman effect

Photoelectric effect

Stark effect

Einstein effect

Question 19 of 20

20. The atoms, molecules or ions that have absorbed radiation are said to be:

absorbed

excited

normal

stable

Question 20 of 20

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