The acceleration due o gravity may be defined as the force
Aof attraction of the sun and on the earth
Bwith which the earth revolves around the sun
Cwith which the earth attracts one kilo-gram mass
Dof the moon on the earth
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Question 472
waec2006
Which of the following actions is necessary in order to tune a string to produce a note of an octave higher than its fundamental?
Adoucling the length of the string
Breducing the tension by half
Creducing the mass per unit length
Dincreasing the tension four times
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Question 473
waec2006
In which of the following media would sound wave travel fastest?
Awood
Bwater
Ciron
Dmercury
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Question 474
waec2006
A travelling microscope is focused on a mark on a table. If a glass block of thickness 18.0cm is placed on the mark by how many centimeters will the microscope be moved upwards so as to focus the mark once again? [refractive index of glass = 1.5]
A27cm
B24cm
C9cm
D6cm
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Question 475
waec2006
Which of the following distances is usually adjustable in the camera? The distance between the
Alens and the film
Bdiaphragm and the shutter
Cshutter and the film
Ddiaphragm and the film
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Question 476
waec2006
A ray from a fixed object is incident on a plane mirror at an angle of 20o. If the mirror is rotated through 30o by how many degree would the reflected ray rotate?
A60o
B50o
C40o
D30o
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Question 477
waec2006
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 478
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 479
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 480
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 481
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 482
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 483
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 484
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 485
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 486
waec2006
The silvered surface in a vacuum flask reduces heat loos due to
Aconduction
Bconvection
Cradiation
Devaporation
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Question 487
waec2006
The sagging of overhead electrical cables is the consequence of
Alinear expansivity
Bsuperficial expansivity
Ccubic expansivity
Dconductivity
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Question 488
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 489
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 490
waec2006
The engine of a train produces a force of 3000N when moving at 30.ms-1. calculate the power of the engine
