Post Utme Physics Past Questions and Answers

Question 241:

Two balls of masses \(40 \mathrm{~g}\) and \(60 \mathrm{~g}\) respectively, are attached firmly to the ends of a light \(m\) rule. The centre of gravity of the system is ____________

A. At the mid-point of the metre rule
B. \(40 \mathrm{~cm}\) from the lighter mass
C. \(40 \mathrm{~cm}\) from the heavier mass
D. \(60 \mathrm{~cm}\) from the heavier mass

Question 242:

Hydrogen molecules escape from the topmost layer of the earth's atmosphere because ____________

A. Hydrogen has negligible mass and has speed above escape velocity
B. The gravitational pull of the earth is negligible in the atmosphere
C. The intermolecular forces in the atmosphere negligible
D. Escape velocity is negligible compared speed of hydrogen molecules

Question 243:

if the refractive index of \(a\) medium is \(2 / \sqrt{3}\), what is the critical angle?

A. \(90^{\circ}\)
B. \(45^{\circ}\)
C. \(60^{\circ}\)
D. \(30^{\circ}\)

Question 244:

The half-life of a radioactive element is 9 days. Calculate the fraction that remains after 36days.

A. \(1 / 16\)
B. \(1 / 32\)
C. \(1 / 8\)
D. \(1 / 64\)

Question 245:

A 12V battery has an internal resistance of 0.5 ohms. If a cable of 1.0 ohms resistance is connected across the two terminals of the battery; the power dissipated is ____________

A. 64W
B. 96W
C. 9.6W
D. 192W