Post Utme Physics Past Questions and Answers

Question 111:

Which of the following statements about friction is NOT correct?

A. The force of kinetic friction is less than the force of static friction.
B. The force of kinetic friction between two surfaces is independent of the areas in contact provided the normal reaction is unchanged.
C. The angle of friction is the angle between the normal reaction and the force friction.
D. The force of rolling friction between two surfaces is less than the force of sliding friction.

Question 112:

Electrical power is transmitted at a high voltage rather than low voltage because the amount of energy loss is 'due to ____________

A. Heat dissipation
B. Production of Eddy current
C. Excessive current discharge
D. Excessive voltage discharge

Question 113:

A ship traveling towards a cliff receives the echo of its whistle after \(3.5\) seconds. A short while later, it receives the echo after \(2.5\) seconds. If the speed of sound in air under the prevailing conditions is \(250 \mathrm{~ms}-1\), how much closer is the ship to the cliff?

A. \(10 \mathrm{~m}\)
B. \(350 \mathrm{~m}\)
C. \(175 \mathrm{~m}\)
D. \(125 \mathrm{~m}\)

Question 114:

A current-carrying conductor experiences a force When placed in a magnetic field because the ____________

A. Conductor is magnetised
B. Magnetic field of the current interacts with external magnetic field
C. Force is due to the motor principle
D. Electric field of the current interacts with external magnetic field

Question 115:

The linear expansivity of brass is \(2 \times 10^{-5} \mathrm{C}^{-1}\). If the volume of a piece of brass is \(15.00 \mathrm{~cm}^{3}\) at \(0^{\circ} \mathrm{C}\), what is the volume at \(100^{\circ} \mathrm{C}\) ?

A. \(16.03 \mathrm{~cm}^{3}\)
B. \(16.00 \mathrm{~cm}^{3}\)
C. \(15.09 \mathrm{~cm}^{3}\)
D. \(15.03 \mathrm{~cm}^{3}\)