Post Utme Physics Past Questions and Answers

Question 96:

The wavelength of signal from a radio transmitter is \(1500 \mathrm{~m}\) and the frequency is \(200 \mathrm{KHz}\).

What is the velocity of the propagation?

A. \(3 \times 10^{8} \mathrm{~ms}^{-2}\)
B. \(7 \times 10^{3} \mathrm{~ms}^{-2}\)
C. \(3 \times 10^{4} \mathrm{~ms}^{-2}\)
D. \(7 \mathrm{~ms}^{-2}\)

Question 97:

A boy on looking into a mirror discovers that his face appeared to have grown bigger. The boy must have been looking at a ____________

A. Convex mirror with his face at the focus
B. Concave mirror with his face between the focus and the mirror
C. Convex mirror with his face between the focus and the mirror
D. Concave minor with his face at this focus

Question 98:

Find the frequencies of the first three harmonics of a piano string of length \(1.5 \mathrm{~m}\), if the velocity of the string is \(120 \mathrm{~m} / \mathrm{s}\).

A. \(40 \mathrm{~Hz}, 80 \mathrm{~Hz}, 120 \mathrm{~Hz}\)
B. \(180 \mathrm{~Hz}, 360 \mathrm{~Hz}, 540 \mathrm{~Hz}\)
C. \(80 \mathrm{~Hz}, 160 \mathrm{~Hz}, 240 \mathrm{~Hz}\)
D. \(36011 \mathrm{z}, 180 \mathrm{~Hz}, 90 \mathrm{~Hz}\)

Question 99:

The resistance of a piece of wire of length \(20 \mathrm{~cm}\) and crosssectional area \(8 \times 10^{5} \mathrm{~m}^{2}\) and resistivity \(4 \times 10^{-7} \Omega \mathrm{m}\) is ____________

A. \(1.0 \Omega\)
B. \(10.0 \Omega\)
C. \(400.0 \Omega\)
D. \(1.0 \times 10-13\)

Question 100:

An electric device is rated \(2000 \mathrm{~W}, 250 \mathrm{~V}\). The correct fuse rating of the device is ____________

A. \(8 \mathrm{~A}\)
B. \(9 \mathrm{~A}\)
C. \(7 \mathrm{~A}\)
D. \(6 \mathrm{~A}\)