Elementary Modern Physics - Jamb Physics Past Questions and Answers

Question 16:

• JAMB 1983

The range of wavelengths of the visible spectrum is 400nm - 700nm. The wavelength of gamma rays is

A. Longer than 700nm
B. Shorter than 700nm but longer then 400nm
C. 550nm
D. Shorter than 400nm
E. Infinite

Question 17:

• JAMB 1983

Which of the following statements is CORRECT? i. the mass number is equal to the total number of protons and electrons in an atom. ii. the atomic number is equal to the number of protons in an atom. iii. the number of electrons in an atom is equal to the total number of protons and neutrons in the nucleus.

A. I only
B. Ii only
C. Iii only
D. I and ii only
E. Ii and iii only

Question 18:

• JAMB 1984

Which of the following statements describes an atom accurately? i. atoms of all elements are identical ii. an atom contains a nucleus and number of electrons iii. due to the electrons in the atom an atom is negatively charged iv. electrons in the atom move in circular orbits round the nucleus

A. I and ii
B. Ii and iii
C. Iii and iv
D. Ii and iv only
E. I,ii and iii

Question 19:

• JAMB 1984

Which of the following i. \(\beta\)-particles ii. protons iii. neutrons iv. \(\alpha\)-particles. may be found in light nuclei?

A. I and ii
B. I and iii
C. Ii and iv
D. Ii and iii
E. I, ii and iii

Question 20:

• JAMB 1984

Which of the following statements is (are) NOT true about the emission of the photoelectrons from metallic surfaces?
i. all metallic surfaces emits the same number of photoelectrons in a given light
ii. most metallic surfaces emit the same number of photoelectrons in visible and infra-red light
iii. a metallic surface emits photoelectrons only if the frequency of the incident light is higher than its own characteristics threshold frequency

A. I only
B. Ii only
C. I and ii
D. Ii and iii
E. Iii only