The lower and upper fixed points of a mecury-in-glass thermometer are marked Y and 180mm respectively. On a particular the mecury meniscus in the thermometer rises to 45mm. If the corresponding reading on a scale is 10o, calculate the value of Y.
A4mm
B18mm
C30mm
D135mm
E450mm
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Question 682
waec1998
An object is heated from 30ºC to 57ºC. The increases in its temperature on the Kelvin scale is
A17k
B27k
C81k
D246k
E300k
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Question 683
waec1998
A ball of mass 5.0kg hits a smooth vertical wall normally with a speed of 2m-1 and rebounds with the same speed. Determine the impulse experienced by the ball
A20.0kgm-1
B5.0kgm-1
C1.3kgm-1
D0.0kgm-1
E10.0kgm-1
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Question 684
waec1998
The earth is not a perfect sphere because its equatorial axis is longer than the polar axis. where on the earth's surface would an object have its greatest weight?
Ahalf way between the equator and the north pole
Bnear the equator
Chalf way between the equator and the south pole
Dat either pole
Eat the equator
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Question 685
waec1998
An object is protected with a velocity of 100m-1 at an angle of 60o to the vertical. Calculate the time taken by the object to reach the highest point (Take g as 10ms-2
A5.0s
B8.7s
C10.0s
D17.3s
E20.0s
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Question 686
waec1998
a pilot records the atmospheric pressure outside his plane as 63cm of Hg while a ground observer records a reading of 75cm of Hg with his barometer. Assuming that the density of air is constant, calculate the height of the plane above the ground. (take the relative densities of air and mecury as 0.00136 and 13.6 respectively)
A120m
B138m
C274m
D1200m
E120,000m
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Question 687
waec1998
I the box is pulled from P to Q, which of the following expresses the velocity ratio of the inclined plane?
APR/PQ
BOR/PQ
COR/PR
DPQ/PR
EPQ/QR
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Question 688
waec1998
If \(\theta\) is equal to \(\alpha\) at the time the box is just about to slide down the plank, the coefficient of static friction between the plank and box is
Asin\(\alpha\)
Bcos\(\alpha\)
Ctan\(\alpha\)
Dsec\(\alpha\)
Ecot\(\alpha\)
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Question 689
waec1998
As the end Q of the plank is raised, the component of W, normal to plank, will
Aincrease
Bdecrease
Cremain the same
Dbe slightly greater than W
Ebe independent of w
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Question 690
waec1998
A rectangular block of wood floats in water with two-thirds of its volume immersed. When placed in another liquid, it floats with half of its volume immersed. Calculate the relative density of the liquid
A1.43
B1.33
C1.00
D0.83
E0.75
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Question 691
waec1998
The term torque means
Athe moment
Bthe resultant of several forces acting on a body in equilibrum
Ctwo equal and oposite forces whose lines of action do not coincide
Dtwo coplaner forces at right angles to each other
Ethe equilibrant of two concurrent forces
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Question 692
waec1998
A piece of stone attached to one end pf string is whirled round in a horizontal circle. When the string is suddenly cut, the stone will
Amove towards te centre of the circle
Bstop moving immediately
Cmove along a circular path of smaller radius
Dfly off in a direction tangential to the circular path
Eacquire greater centripetal force
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Question 693
waec1998
which of the following pairs of physical quantities comprises vectors?
Acapacitance and inductance
Bforce ratio and velocity ratio
Cfriction and momentum
Denergy and power
Eelectric field potential and electric field intensity
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Question 694
waec1997
An atom radiates 1.5 x \(10^{-19}\)J of energy when an electron jumps from one energy level to another. What is the wavelength of the emitted radiation? (Planck’s constant =6.6 x \(10^{-34}\)Js. Speed of light in air=3 x \(10^{8}ms^{-1}\)
A1.32 x \(10^{-6}\)m
B2.98 x \(10^{-6}\)m
C3.32 x \(10^{-6}\)m
D6.82 x \(10^{-6}\)m
E8.01 x \(10^{-6}\)m
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Question 695
waec1997
In a nuclear reaction, the mass defect is 2 x \(10^{-6}\)g. Calculate the energy released given that the velocity of light is 3 x \(10^{8}ms^{-1}\)
A9 x \(10^{7}\)J
B1.8 x \(10^{8}\)J
C1.8 x \(10^{9}\)J
D9 x \(10^{-10}\)J
E3.6 x \(10^{11}\)J
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Question 696
waec1997
During the electrolysis of copper (II) tetraoxosulphate (VI) solution, an ammeter shows a steady reading of 1A for 30minutes while 6.6 x \(10^{-4}\)kg of copper is liberated. Calculate the error in the ammeter The electrochemical equivalent of copper is 3.30 x \(10^{-7}kgC{-1}\)
A0.001A
B0.011A
C0.111A
D1A
E1.1A
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Question 697
waec1997
A capacitor of capacitance 25µF is connected to an a.c power source of frequency 200/πHz. Calculate the reactance of the capacitor
A0.01Ω
B0.02Ω
C50Ω
D100Ω
E150Ω
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Question 698
waec1997
A charge of 1 x \(10^{-5}\)C experiences a force of 40N at a certain point in space. What is the magnitude of the electric field intensity at the point in Newton and couloumb
A8 x \(10^{6}\)
B4 x \(10^{6}\)
C3 x \(10^{-4}\)
D2 x \(10^{-4}\)
E5 x \(10^{-7}\)
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Question 699
waec1997
The current in a series R-L-C circuit attains its maximum value when the
AImpedance is greater than the capacitive reactance
BInductive reactance is equal to the capacitive reactance
CInductive reactance is greater than the capacitive reactance
Dcapacitive reactance is less than resistance
EInductive reactance is greater than the capacitive reactance
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Question 700
waec1997
A magnet is being inserted into a coil of wire. On which of the following factors does the induced e.m.f in the coil depend? I. Number of turns in the coil II. Strength of the coil III. Speed with which magnet is inserted into the coil.
