1kg of copper is transferred quickly from boiling water to a block of ice. Calculate the mass of ice melted, neglecting heat loss. [specific heat capacity of copper 400Jkg-1K-1 and latent heat of fusion of ice 333 x 103Jkg-1]
A60g
B67g
C120g
D133g
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Question 2032
jamb1990
The pressure of a gas when cooled at constant volume will decrease because the molecules
Acollide less frequently with the walls of the container
Bhave the same average kinetic energy
Cbreak up into smaller molecules
Ddecrease in number
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Question 2033
jamb1990
A bar of initial length /0 is heated through a temperature change \(\Delta\)t to a new length I. The linear expansivity, a, of the bar is
A\(\frac{/ - /_o}{/ \Delta t}\)
B\(\frac{/ - /_o}{/_o \Delta t}\)
C/o(1 + \(\Delta\) t)
D\(\frac{/ - /_o}{/(1 + \Delta t)}\)
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Question 2034
jamb1990
The resistances of platinum wire at the ice and steam points are 0.75 ohm and 1.05 ohm respectively. Determine the temperature at which the resistance of the wire is 0.90 ohm
A43.0oC
B50.0oC
C69.9oC
D87.0oC
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Question 2035
jamb1990
40m3 of liquid is mixed with 60m3 of another liquid Q. If the density of P and Q are 1.00kgm-3 and 1.6kgm-3 respectively, what is the density of the mixture?
A0.05kgm-3
B1.25kgm-3
C1.30kgm-3
D1.36kgm-3
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Question 2036
jamb1990
What is the length of liquid column in a barometer tube that would support an atmospheric pressure of 102000Nm-2 if the density of the liquid is 2600kgm-3? [g = 10ms-2]
A0.75m
B0.76m
C3.92m
D39.23m
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Question 2037
jamb1990
An inclined plane which makes an angle of 30o with the horizontal has a velocity ratio of
A2
B1
C0.866
D0.50
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Question 2038
jamb1990
A body of mass 10kg rests on a rough inclined plane whose angle of tilt \(\theta\) is variable. \(\theta\) is gradually increased until the body starts to slide down the plane at 30o. The coefficient of limiting friction between the body and the plane
A0.30
B0.50
C0.58
D0.87
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Question 2039
jamb1990
A stone of mass m kg is held h meters above the floor for 50s. The work done in joules over this period is
Amh
Bmgh
C\(\frac{mgh}{50}\)
DO
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Question 2040
jamb1990
To keep a vehicle moving at a constant speed v, requires power P, from the engine. The force provided by the engine is
A\(\frac{p}{v}\)
B\(\frac{1}{2}\) v
Cpv
D\(\frac{p}{v^2}\) v
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Question 2041
jamb1990
Which of the following statements are correct about an object in equilibrium under parallel forces? i. the total clockwise moments of the forces about any point equals the total anti-clockwise moments about the same point. ii. the total forces in one direction equals the total forces in the opposite direction. iii. the resolved components along the x-axis equals the resolved components along the y-axis.
Ai and ii only
Bi and iii only
Cii and iii
Di, ii, and iii only
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Question 2042
jamb1990
A particle of mass M which is at rest splits up into two. If the mass and velocity of one of the particles are m and v respectively, calculate the velocity of the second particle
A\(\frac{mv}{M}\)
B\(\frac{Mv}{M - m}\)
C\(\frac{mv}{M + m}\)
D\(\frac{mv}{M - m}\)
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Question 2043
jamb1990
A car moving with a speed of 90kmh\(^{-1}\) was brought uniformly to rest by the application of the brakes in 10s. How far did the car travel after the brakes were applied?
A125m
B150m
C250m
D15km
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Question 2044
jamb1990
Which of the following is a fundamental unit?
ANewton
BWatt
CJoule
DSecond
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Question 2045
waec1989
The electric force between two point charges each of the magnitude, q at a distance of r apart in air of permittivity is:
Aq2/4πεr
Brε0/q2
C4πq/ε0
Dqr2/ε0
E\(\frac{q^2}{4\piεor^2}\)
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Question 2046
waec1989
Calculate the escape velocity for a rocket fired from the earth's surface at a point where the acceleration due to gravity is 10ms-2 and the radius of the earth is 6 x 106m.
A7.8 x 106ms-12
B1.1 x 104ms-1
C3.5 x 107ms-1
D6.0 x 107 ms-1
E1.2 x 108ms2-1
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Question 2047
waec1989
What is the gravitational potential due to a molecule of mass, m and at a distance, r from it? (G = gravitational constant).
AGm2/r2
BGm/r
CGm2/r
DG2m2/r
Em2/Gr2
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Question 2048
waec1989
Which of the following is not a property of longitudinal waves?
Acompression
Breflection
Crefraction
Dpolarization
Ediffraction
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Question 2049
waec1989
A string is stretched between two points 50cm apart. It is then plucked at its center and the velocity of the wave produced is 300m/s. Calculate the number of vibrations made by the string in 1s.
A3
B6
C150
D300
E600
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Question 2050
waec1989
In a wave the maximum displacement of particles from their equilibrium positions is called.
