Questions and answers for exam Preparation

MCQs

Total Questions : 78 | Page 3 of 8 pages

Question 21. If the absorption of electromagnetic radiation by matter results in the emission of radiation of the same or longer wavelengths for a long time, the phenomenon is termed as which of the following?

Luminescence
Fluorescence
Phosphorescence
Spontaneous emission

Discuss Question

Answer: Option C. -> Phosphorescence
Answer: (c).Phosphorescence

Question 22. Which of the following is Mosely’s equation if ‘C’ is the speed of light, ‘a’ is proportionality constant, ‘σ’ is a constant which depends on electronic transition series, ‘Z’ is the atomic number and ‘λ’ is the wavelength?

Cλ= a(Z-σ)²
C/λ= a(Z-σ)²
C(Z-σ)²= aλ
C(Z-σ)²= a/λ

Discuss Question

Answer: Option B. -> C/λ= a(Z-σ)²
Answer: (b).C/λ= a(Z-σ)²

Question 23. The energy of the emitted X-rays depends upon the _________ of the atom and their intensity depends upon the __________

Atomic number, amount of sample
Mass number, amount of sample
Mass number, concentration of atoms
Atomic number, concentration of atoms

Discuss Question

Answer: Option D. -> Atomic number, concentration of atoms
Answer: (d).Atomic number, concentration of atoms

Question 24. The measurement of intensity of fluorescent X-rays provide a simple and ____________ way of _____________ analysis.

Destructive, quantitative
Non-destructive, quantitative
Destructive, qualitative
Non-destructive, qualitative

Discuss Question

Answer: Option B. -> Non-destructive, quantitative
Answer: (b).Non-destructive, quantitative

Question 25. Prompt emission of X-ray by an atom ionised by a higher energy X-ray is a type of which of the following phenomena?

Luminescence
Fluorescence
Phosphorescence
Spontaneous emission

Discuss Question

Answer: Option B. -> Fluorescence
Answer: (b).Fluorescence

Question 26. Which of the following is not a target metal used in the Coolidge tube?

Rhodium
Cobalt
Gold
Silver

Discuss Question

Answer: Option C. -> Gold
Answer: (c).Gold

Question 27. When compared to filters, monochromators provide much signal to noise ratio.

True
False
May be True or False
Can't say

Discuss Question

Answer: Option A. -> True
Answer: (a).True

Question 28. How can the resolution of the collimator be increased?

By reducing the separation between the metal plates of the collimator
By increasing the separation between the metal plates of the collimator
By increasing the number of metal plates
By decreasing the number of metal plates

Discuss Question

Answer: Option A. -> By reducing the separation between the metal plates of the collimator
Answer: (a).By reducing the separation between the metal plates of the collimator

Question 29. Which of the following crystals are not suited for x-ray grating?