In which of the following are the substance arranged in descending order of their thermal conductivities?
Acopper, steel, glass
Bsteel, copper, glass
Csteel, glass, copper
Dcopper, glass, steel
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Question 2142
jamb1987
22,000J of heat is required to raise the temperature of 1.5kg of paraffin from 20oC to 30oC. Calculate the specific heat capacity of paraffin.
A1466Jkg-1oC-1
B2933Jkg-1oC-1
C4400Jkg-1oC-1
D5866Jkg-1oC-1
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Question 2143
jamb1987
Hot water is added to three times its mass of water at 10oC and the resultant temperature is 20oC. What is the initial temperature of the hot water?
A100oC
B80oC
C50oC
D40oC
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Question 2144
jamb1987
As a result of air at the top of a barometer, the height of the mercury column is 73.5cm when it should be 75.0cm; the volume of the space above the mercury is 8.0cm3. Calculate the correct barometer height when the barometer reads 74.0cm and the volume of the space above the mercury is 6.0cm3.
A72.0cm
B74.5cm
C75.1cm
D76.0cm
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Question 2145
jamb1987
The length of a side of a metallic cube at 20ºC is 5.0cm. Given that the linear expansivity of the metal is 4.0 x 10\(^{-5}\)k\(^{-1}\), find the volume of the cube at 120°C.
A126.50cm3
B126.25cm3
C126.00cm3
D125.00cm3
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Question 2146
jamb1987
The distance between the fixed points of a centigrade thermometer is 20cm. What is the temperature when the mercury level is 4.5cm above the lower mark?
A22.5oC
B29.0oC
C90.0oC
D100.0oC
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Question 2147
jamb1987
A cube of side 10cm and mass 0.5kg floats in a liquid with only \(\frac{1}{5}\) of its height above the liquid surface. What is the relative density of the liquid?
A0.125
B0.250
C0.625
D2.500
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Question 2148
jamb1987
A load of 5N gives an extension of 0.56cm in a wire which obeys Hooke's law. What is the extension caused by a load of 20N?
A1.12cm
B2.14cm
C2.24cm
D2.52cm
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Question 2149
jamb1987
The mechanical advantage(MA) of an inclined plane depends on
Aits length
Bits height
Cthe product of its length and height
Dthe ratio of its length to its height
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Question 2150
jamb1987
If a beaker is filled with water it is observed that the surface of the water is not horizontal at the glass-water interface. This behavior is due to
Afriction
Bviscosity
Csurface tension
Devaporation
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Question 2151
jamb1987
The coefficient of static friction between a 40kg crate and concrete surface is 0.25. Find the magnitude of the minimum force needed to keep the crate stationary on the concrete base inclined at 45o to the horizontal. [G = 10ms-1]
A400N
B300N
C283N
D212N
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Question 2152
jamb1987
A body rolls down a slope from a height of 100m. its velocity at the foot of the slope is 20ms-1. What percentage of its initial potential energy is converted into kinetic energy? [g = 10ms-1]
A40%
B35%
C20%
D15%
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Question 2153
jamb1987
A constant force of 40N acting on a body initially at rest gives an acceleration of 0.1ms-2 for 4s. Calculate the work done by the force
A8J
B10J
C32J
D160J
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Question 2154
jamb1987
An elevator of mass 4800kg is supported by a cable which can safely withstand a maximum tension of 60 000N. The maximum upward acceleration the elevator can have is
A2.5ms-2
B5.0ms-2
C7.5ms-2
D10.0ms-2
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Question 2155
jamb1987
A man walks 8km north and then 5km in a direction 60o east of north. Find the distance from his starting point
A11.36km
B12.36km
C13.00km
D14.36km
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Question 2156
jamb1987
A jet engine develops a thrust of 270Ns when the velocity of the exhaust gases relative to the engine is 300ms-1. What is the mass of the material ejected per second?
A81.00kg
B9.00kg
C0.90kg
D0.09kg
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Question 2157
jamb1987
Which of the following units is equivalent to kgms-1?
ANs-1
BNms-1
CNs
DJs-1
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Question 2158
jamb1986
fig 1 is a graph of force against extension for a spiral spring, the force constant of the spring is given by the
Aslope of the linear prtion of the graph
Blength of the linear portion of the graph
Carea under the linear portion of the graph
Darea under the entire graph
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Question 2159
jamb1986
A uniform meter rule QR is balanced on a knife edge which is 55cm from R, when a mass of 10g is hung at P as shown above, the mass of the meter rule is
A550g
B350g
C70g
D35g
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Question 2160
jamb1986
In fig 3, three forces F1, F2, and F3 acting at O are in equilibrium. If the magnitude of F1 is 10N,and the magnitude of F2 is 5N, find the magnitude of F3
