Question 706:

• JAMB 1992

After three half lifes, the fraction of a radioactive material that has decayed is

A. \(\frac{1}{8}\)
B. \(\frac{1}{3}\)
C. \(\frac{2}{3}\)
D. \(\frac{7}{8}\)

Question 707:

• JAMB 1992

\(^{27}_{13}Al\) + \(^{1}_{0}n\) \(\Rightarrow\) \(^{24}_{11}Na\) + X

A. A proton
B. A gamma ray
C. A helium particle
D. An alpha particle

Question 708:

• JAMB 1992

A uniform light rod is kept in horizontal equilibrium under the influence of fore forces as shown above, which of the following equations correctly represents the condition of equilibrium for the rod

A. F1 + F2 = F3 + F4
B. F1 + F2 - F3 + F = 0
C. (F1 + F2)ab = (F3 + F4)cd
D. F1a + F2b - F3c - F4d = 0

Question 709:

• JAMB 1992

In the diagram above, the hanging mass m2 is adjusted until m1 is on the verge of sliding. The coefficient of static friction between the mass m1 and the table is

A. M1/m2
B. M1g/m2
C. M2/m1
D. M2g/m1

Question 710:

• JAMB 1992

The fig above shows the heights of two liquids X and Y when some air is sucked out of the apparatus through the pump P. The diameter of the table in X is twice That of the Tube In Y. What is the relative density of the liquid X with respect to liquid Y

A. 1/3
B. 2/3
C. 3
D. 6