Elementary Modern Physics - Jamb Physics Past Questions and Answers

Question 26:

• JAMB 1987

Which of the following statements is TRUE of photoelectric effect?

A. It cannot occur in liquids
B. The energy of the emitted electrons is independent of the work function of the surface
C. The energy of the emitted electron depends on the wavelength of the incident light
D. The greater the intensity of the incuident light, the greater the incident of the emitted electron

Question 27:

• JAMB 1987

Isotopes are nuclei which have

A. The same number of nuetrons and electrons
B. Equal number of electrons and protons
C. The same atomic number but different number of neutrons
D. The same number of total particles

Question 28:

• JAMB 1987

A radioactive sample initially contains N atoms. After three half-lives the number of atoms that have disintegrated is

A. \(\frac{N}{8}\)
B. \(\frac{3N}{8}\)
C. \(\frac{5N}{8}\)
D. \(\frac{7N}{8}\)

Question 29:

• JAMB 1988

Which of the following statement is TRUE of ultraviolet, visible and infra-red rays?

A. They are all electromagnetic waves with the same wavelength
B. Ultra-violet rays have shorter wavelengths than infra-red rays and produce flourescence
C. Infrared rays have shorter wavelength than visible light and produce the sensation of heat
D. The wavelenghts increase in the sequence: visible, ultra-violet, infra-red

Question 30:

• JAMB 1988

In a certain fusion reaction, a deuteron (\(^{2}_{1}H\)) interacts with a triton (\(^{3}_{1}He\)) and produces an a-particle (\(^{4}_{2}He\)) and a second product. The second product is

A. A proton
B. An electron
C. A neutron
D. A gamma ray