D\(\frac{\text{wavelength in air}}{\text{wavelength in water}}\)
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Question 865
waec2010
From the diagram, the correct equation for the refractive index n of the medium is
An = tan i
Bn = \(\frac{sin i}{sin 90^o}\)
Cn = \(\frac{sin i}{cos (90^o - i)}\)
Dn = sin 90oC
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Question 866
waec2010
When an object is placed at the principal focus of a concave mirror, the location of the image formed is
Abetween principal focus and pole
Bbetween principal focus and centre of curvature
Cat infinity
Dat centre of curvature
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Question 867
waec2010
The following devices use plane mirrors in their operations, except
Aperiscope
Bsextant
Ckaleidoscope
Dbinoculars
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Question 868
waec2010
The ability of a wave to spread around corners is called
Apolarisation
Bdispersion
Cdiffraction
Dreflection
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Question 869
waec2010
A certain wave has a speed of 20ms-1. If the frequency of the wave is 0.25Hz, calculate the distance between successive crests of the wave
A5.0m
B40.0m
C50.0m
D80.0m
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Question 870
waec2010
Dew point is not affected by
Atemperature
Bwind
Cthe amount of water vapour in the atmosphere
Datmospheric pressure
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Question 871
waec2010
A solid of mass 0.5kg initially at 50oC melts at 60oC. Calculate the quantity of heat required to melt it completely. [specific heat capacity of the solid =2.0KJ kg-1K-1][Specific latent heat of fusion of solid =1.0 KJ kg-1]
A1500J
B10000J
C10500J
D15000J
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Question 872
waec2010
An electric drill rated 400W is used to drill a hole in copper of mass 400g in 20s. Calculate the rise in temperature if all the heat produced is absorbed by the copper. [specific heat capacity of copper = 400Jkg-1K-1]
A100oC
B75oC
C50oC
D45oC
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Question 873
waec2010
Specific heat capacity 36.4 Jkg-1 K-1 of a body means that when 36.4J of heat energy is supplied to a body of
Amass 100kg the temperature rises by 1k
Bmass 1kg, the temperature by 1000K
Cmass 1kg, the temperature rises by 1K
Dmass 100kg, the temperature rises by 1000k
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Question 874
waec2010
The pressure P, volume V, and absolute temperature T of a given mass of an ideal gas change simultaneously. Which of the followng equations is correct about the gas?
APV = \(\frac{constant}{T}\)
B\(\frac{P}{T} = Constant\)
C\(\frac{P}{V} = \frac{constant}{T}\)
D\(\frac{I}{T} = \frac{constant}{PV}\)
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Question 875
waec2010
In a thermos flask, heat loss by radiation is minimizes by the
Asilvered surfaces
Bvacuum within the doubled walls
Cplastic stopper
Dcork support
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Question 876
waec2010
The advantages of the thermoelectric thermometer include the following characteristics except that it
Acan measure rapidly changing temperatures
Bcan measure high and low temperature
Ccan measure high and low temperature almost at a point
Dis fairly sensitive
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Question 877
waec2010
a thermometer records 680 mmHg at steam point and 440 mmHg at ice point. The temperature it records at 380 mmHg is
A-25oC
B-20oC
C20oC
D25oC
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Question 878
waec2010
a machine is said to be a third class lever when the
Aload is between the fulcrum and effort
Bfulcrum is between the effort and the load
Ceffort is between the fulcrum and load
Dfulcrum is directly below the load
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Question 879
waec2010
Which of the following sources of energy is/are exhausible? i. Solar ii. Fossil fuels iii. Tidal power
Aii, and iii
Bi and ii only
Ci and iii only
Dii only
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Question 880
waec2010
A moving body of mass 25.0kg undergoes a uniform retardation of 20.0ms-2. Calculate the magnitude of the retardating force
