1994 - WAEC Physics Past Questions and Answers - page 5

41
A light wave travels from air into a medium of refractive index 1.54. If the wavelength of the light in air is \(5.9\times10^{-7}\)m, calculate its wavelength in the medium
A
\(2.5\times10^{-7}\)m
B
\(3.8\times10^{-7}\)m
C
\(4.6\times10^{-7}\)m
D
\(5.2\times10^{-7}\)m
42
The density of a body is \(5\times10^3kgm{^-3}\) and it weighs 1N in air. Calculate the apparent weight of the body when totally immersed in water. (Density of water =\(10^3kgm{-3}, g= 10ms^{-2}
A
0.02N
B
0.08N
C
0.20N
D
0.80N
43
The density of water is 1g\(cm^3\) while that of ice is 0.9\(cm^3\), calculate the volume change when 90g of ice is completely melted
A
0\(cm^3\)
B
9\(cm^3\)
C
10\(cm^3\)
D
90\(cm^3\)
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