A metal rod 800mm long is heated from 10oC to 95oC. If it expands by 1.36mm, the linear expansivity of the metal is
A2.0 x 102K-1
B2.0 x 102K-1
C5.0 x 10-3K-1
D2.0 x 10-5K-1
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Question 1872
jamb1993
The thermometric properties of the thermocouple is that is
Ae.m.f. changes with temperature
Bresistance changes with temperature
Cvolume changes with temperature
Dpressure changes with resistance
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Question 1873
jamb1993
An object of mass 400g and density 600kgm-3 is suspended with a sting so that half of it is immersed in paraffin of density 900kgm-3. The tension in the string is
A1.0N
B3.0N
C4.0N
D5.0N
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Question 1874
jamb1993
A weightless vessel of dimensions 4m x 3m x 2m is filled with a liquid of density 1000kgm\(^{-3}\) and sealed. What is the maximum pressure this container can exert on a flat surface? [g = 10ms\(^{-2}\)]
A9 x 104Nm-2
B4 x 104Nm-2
C3 x 104Nm-2
D2 x 104Nm-2
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Question 1875
jamb1993
A plane inclined at angle \(\theta\) has a velocity ratio of 10 : 1. The inclination of the plane to the horizontal is given by
Atan\(\theta\) = \(\frac{1}{10}\)
Bcot\(\theta\) = \(\frac{1}{10}\)
Ccos\(\theta\) = \(\frac{1}{10}\)
Dsin\(\theta\) = \(\frac{1}{10}\)
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Question 1876
jamb1993
Which of the following correctly describes the energy changes in the generation of light by a hydroelectric power station?
The force experienced by an object of mass 60.0kg in the moon's gravitational field is 1.002 x 102N. What is the intensity of the gravitational field?
A0.60Nkg-1
B1.67Nkg-1
C6.12 x 102Nkg-1
D9.81ms-2
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Question 1878
jamb1993
A rocket burns fuel at the rate of 10kgs-1 and ejects it with velocity of 5 x 103ms-1. The thrust exerted by the gas on the rock is
A2.5 x 107N
B5.0 x 104N
C5.0 x 102N
D2.0 x 10-3N
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Question 1879
jamb1993
Two forces of magnitudes 7N and 3N act at right angles to each other. The angle \(\theta\) between the resultant and the 7N force is given by
Acos\(\theta\) = \(\frac{3}{7}\)
Bsin\(\theta\) = \(\frac{3}{7}\)
Ctan\(\theta\) = \(\frac{3}{7}\)
Dcot\(\theta\) = \(\frac{3}{7}\)
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Question 1880
jamb1993
The external and internal diameter of a tube are measured as (32 ± 2)mm and (21 ± 1)mm respectively. Determine the percentage error in the thickness of the tube.
A27%
B14%
C9%
D3%
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Question 1881
jamb1993
Which of the following quantities has the same unit as the watt?
AForce x time
BForce x distance
CForce x acceleration
DForce x velocity
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Question 1882
waec1992
An electric string of length l is elastically stretched through a length e by a force F. The area of cross- section of the string is A and its Young’s modulus is E. Which of the following expressions is correct?
AF = EA/eI
BF = EAI/e
CF = EAe/l
DF = EAe
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Question 1883
waec1992
The process by which a metal, heated to high temperature, gives off electrons from its surface is known as
Aphotoelectric emission
Bthermionic emission
Cradioactive emission
DHeld emission
Esecondary emission
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Question 1884
waec1992
A sheet of paper is placed in the path of a beam of radiations from a radioactive source. Which of the following radiations will pass through the paper?I. Alpha rays II. Beta rays III. Gamma rays
AI only
BII only
CIII only
DII and III only
EI, II and III
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Question 1885
waec1992
When the nucleus of a uranium atom is split into two fragments of nearly equal mass the sum of the masses of the fragments is less than the mass of the original nucleus. This difference is a measure of the
Aexperimental error in calculating the separate masses
Bchange of momentum of each fragment
Cpotential energy lost
Dnuclear energy released
Ekinetic energy lost
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Question 1886
waec1992
An element whose half-life is 3 years has N atoms. How many atoms would have decayed after 9 years
A1 N atoms8
B1 N atoms3
C2 N atoms3
D5 N atoms6
E7 N atoms8
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Question 1887
waec1992
A stream of alpha particles is projected into an electric field between two plates X and Y as shown in the diagram above. Which of the following is correct? The particles are
Aaccelerated and they continue in a straight line
Bdirectionally reversed at the end of the plates
Cdeflected towards plate Y
Dattracted by both plates
Edeflected towards plate X.
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Question 1888
waec1992
Which of the following gives rise to the line spectra obtained from atoms?
AKinetic energy of a moving atom
BPotential energy of an electron inside an atom
CChange of an electron from a higher to a lower energy level in the atom
DDisturbed proton in the nucleus
EExcitation of an electron in the atom
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Question 1889
waec1992
Which of the following statements is correct about cathode rays? They are fast moving
Aatoms
Bions
Cneutrons
Dprotons
Eelectrons
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Question 1890
waec1992
lf the frequency of the a.c. circuit illustrated is 500Hz/ π what would be the reactance in the circuit?
