Post Utme Physics Past Questions and Answers

Question 1071:

A body of mass \(1.5 kg\) is fastened to a spring, and lies on a horizontal frictionless table. When the mass is pulled with a force of \(32 N\), the extension in the spring is \(0.35 m\). Calculate the maximum kinetic energy for a simple harmonic oscillation when the initial displacement is \(0.2 m\).

A. 9.80J
B. 9.44J
C. \(1.83 J\)
D. \(0.45 J\)

Question 1072:

The linear coefficient of expansion of aluminium is \(23 \times\) \(10-60 C ^{-1}\), and that of iron is \(11 \times 10^{-60} C ^{-1}\). The length of an aluminium rod is \(0.24\) times the length of an iron rod when both are at \(0^{\circ} C\). The temperature of the aluminium rod is increased to \(60^{\circ} C\) while that of the iron rod is increased to \(45^{\circ} C\). Calculate the ratio of the increase in length of the aluminium rod to that of the iron rod.

A. \(1.00: 0.67\)
B. \(1.00: 1.49\)
C. \(4.00: 3.00\)
D. \(2.10: 1.00\)

Question 1073:

In a thermo-flask, cork is placed between the evacuated inner cylinder and the outer jacket to reduce heat loss or gain due to ____________ process.

A. Combustion
B. Convection
C. Radiation
D. Conduction

Question 1074:

The process of ejecting electrons from a body by heating it is referred to as ____________

A. Thermionic emission
B. Photoelectric effect
C. Electron conduction
D. Thermal conduction

Question 1075:

Which of the following bodies will lose its heat at the fastest rate? The bodies have the same surface area and initial temperature.

A. A sphere painted black and dull in appearance
B. A cube painted glossy white
C. A toroid painted shiny black
D. A sphere panted shining red