The distance between the successive crests of a wave travelling at 20ms\(^{-1}\) is 25cm. Calculate the frequency of the wave
A0.8Hz
B5.0Hz
C50.0Hz
D80.0hz
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Question 12
waec2006
Which of the following observations cannot be explained using the rectilinear propagation of light?
Aproduction of images by a pinhole camera
Bproduction of real images of objects by lenses
Cformation of an annular eclipse
Ddiffraction patterns of light
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Question 13
waec2006
The eclipse of the moon occurs when the
Amoon comes exactly between the earth and the sun
Bearth comes exactly between the moon and the sun
Csun comes exactly between the earth and the moon
Dmoon reflects all the rays from the sun onto the earth
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Question 14
waec2006
a note of frequency 2000Hz has a velocity of 400 ms-1. calculate the wavelength of the note
A5.0m
B2.0m
C0.5m
D0.2m
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Question 15
waec2006
The S.I units of frequency, period and amplitude of a wave are respectively
Ahertz, second and centimeter
Bsecond, metre and hertz
Cmetre, hertz and seconds
Dhertz, second and metre
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Question 16
waec2006
The temperature of a liquid falls after some of it has evaporated because
Athe liquid left is smaller in volume and the breeae easily cools it
Bthe more energetic molecules have escaped into the atmosphere
Cthe liquid left has less latent heat
Dafter evaporation impurites are left behind
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Question 17
waec2006
A quantity of steam at 100oC condenses to water at the same temperature by releasing 6.9 x 104J of energy. Calculate the mass of the condensed steam. [specific latent heat of vaporization of eater = 2.3 x 106 J kg-1]
A3.0 x 10-1 kg
B3.0 x 10-2 kg
C3.0 x 10-3 kg
D3.0 x 10-4 kg
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Question 18
waec2006
The amount of energy required to change a kilogram of ice in water without a change in temperature is
Aheat capacity of ice
Bspecific heat capacity
Cspecific latent heat of vaporisation of ice
Dspecific latent heat of fusion of ice
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Question 19
waec2006
How long will it take to heat 3kg of water from 28oC to 88oC in an electric kettle taking 6a from a 220V supply? [specific heat capacity of water = 4180 J kg-1K-1]
A120s
B570s
C600s
D836s
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Question 20
waec2006
The silvered surface in a vacuum flask reduces heat loos due to
Aconduction
Bconvection
Cradiation
Devaporation
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Question 21
waec2006
The sagging of overhead electrical cables is the consequence of
Alinear expansivity
Bsuperficial expansivity
Ccubic expansivity
Dconductivity
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Question 22
waec2006
A block and tackle system has six pulleys. a force of 50N applied to it lifts a load of weight W. If the efficiency of the system is 40%, calculate W
A300N
B200N
C140N
D120N
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Question 23
waec2006
The velocity ratio of an inclined plane, inclines at an angle \(\theta\) to the horizontal can be expressed as
A(sin \(\theta)^{-1}\)
B\(\sin \theta\)
C(cos \(\theta)^{-1}\)
D\(\cos \theta\)
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Question 24
waec2006
The engine of a train produces a force of 3000N when moving at 30.ms-1. calculate the power of the engine
A1.00 x 102W
B3.00 x 104W
C9.00 x 104W
D3.00 x 105W
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Question 25
waec2006
The potential energy in an elastic string of force constant K which has been extended by X metres is expresses as
A\(\frac{1}{2}k \Box ^2\)
B\(k \Box ^2\)
C\(\frac{1}{2}k \Box \)
D\(k \Box \)
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Question 26
waec2006
Which of the following statements about the mouth piece of a telephone is correct? It converts sound energy into
Aacoustic energy
Bmechanival energy
Celectrical energy
Dheat energy
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Question 27
waec2006
A stone of mass 2.0kg is thrown vertically upward with a velocity of 20.0 ms-1, calculate the initial kinetic energy of the stone
A200J
B400J
C800J
D1600J
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Question 28
waec2006
Which of the following source of energy is renewable?
Apetroleum
Bcharcoal
Chydro
Dnuclear
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Question 29
waec2006
A force acting on a body causes a change in the momentum of a body from 12 kg ms-1 to 16kg ms-1 in 0.25. Calculate the magnitude of the impulse
A28.0Ns
B20.0Ns
C4.0Ns
D0.8Ns
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Question 30
waec2006
which of the following statements about simple harmonic motion is correct? The
Atotal mechanical energy is always conserved
Blinear acceleration is directed to any variable point
Clinear acceleration varies inversely with displacement
Dperiod of oscillation varies linearly as acceleration due to gravity
