Atomic absorption spectrophotometer mcq

  Atomic absorption spectrophotometer

1. Which of the following is the principle of Atomic Absorption Spectroscopy?

a) Radiation is absorbed by non-excited atoms in vapour state and are excited to higher states

b) Medium absorbs radiation and transmitted radiation is measured

c) Colour is measured

d) Colour is simply observed

Answer: Radiation is absorbed by non-excited atoms in vapour state and are excited to higher states

2. In Atomic Absorption Spectroscopy, which of the following is the generally used radiation source?

a) Tungsten lamp

b) Xenon mercury arc lamp

c) Hydrogen or deuterium discharge lamp

d) Hollow cathode lamp

Answer: Hollow cathode lamp

3. In Atomic Absorption Spectroscopy, with what material is the cathode in Hollow cathode lamp constructed?

a) Tungsten

b) Quartz

c) Element to be investigated

d) Aluminium

Answer: Element to be investigated

4. How can the intensity of radiation be increased in Hollow cathode lamp?

a) Addition of non-conductive protective shield of mica

b) Addition of nitrogen to neon or argon in the lamp

c) Increasing the pressure of the filling gas

d) Changing the metal of the anode

Answer: Addition of non-conductive protective shield of mica

5. Which of the following is the function of the chopper in Atomic Absorption Spectroscopy?

a) To split the beam into two

b) To break the steady light into a pulsating light

c) To filter unwanted components

d) To reduce the sample into atomic state

Answer: To break the steady light into a pulsating light

6. Which of the following is the function of the Flame or Emission system in Atomic Absorption Spectroscopy?

a) To split the beam into two

b) To break the steady light into pulsating light

c) To filter unwanted components

d) To reduce the sample into atomic state

Answer: To reduce the sample into atomic state

7. Atomic absorption spectroscopy is also called as Absorption Flame Photometry.

a) True

b) False

Answer: True

8. Which of the following is not a component of the emission system in Flame photometer?

a) Burner

b) Atomiser

c) Fuel gases and their regulation

d) Chopper

Answer: Chopper

9. Which of the following is the function of the atomiser in the emission system of Atomic Absorption Spectroscopy?

a) To split the beam into two

b) To break the steady light into pulsating light

c) To break large mass of liquid into small drops

d) To reduce the sample into atomic state

Answer: To break large mass of liquid into small drops

10. Which of the following is not a fuel used in flame photometry?

a) Acetylene

b) Propane

c) Hydrogen

d) Camphor oil

Answer: Camphor oil

11. Which of the following is not the requirement of a good flame in flame photometer?

a) Liquid sample must be evaporated to form solid residue

b) Solid residue must decompose to form atoms

c) Atoms must be produced such that they have the ability to get excited to higher states

d) Atoms must be produced such that they are in stable state

Answer: Atoms must be produced such that they are in stable state

12. Atomic Absorption Spectroscopy is used for the analysis of metals.

a) True

b) False

Answer: True

13. Which of the following options explains the process of ‘sputtering’ that occurs in Hollow Cathode Lamp?

a) Positive ions collide with cathode surface and metal atoms from cathode are ejected

b) Negative ions collide with cathode surface and metal atoms from anode are ejected

c) Positive ions collide with negative ions and metal atoms from anode are ejected

d) Positive ions collide with negative ions and photons are ejected

Answer: Positive ions collide with cathode surface and metal atoms from cathode are ejected

14. At what pressure should the gases in the sealed tube be maintained in the Hollow cathode lamp?

a) 1 to 5 torr

b) 20 to 30 torr

c) 40 to 50 torr

d) 50 to 55 torr

Answer: 1 to 5 torr