Water in an open container boils at a lower temperature when heated at the top of a mountain than at sea-level because at the top of a mountain
Apressure is increased
Bpressure is reduced
Cthe rays of the sun add more heat to the water
Dthe saturation vapour pressure of water is higher than at sea-level
Ethe temperature is lower than at sea-level
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Question 72
neco2003
J.J. Thomson’s model of the atom was abandoned because
Ait could not explain the scattering of alpha particles
Bit did not account for the neutron
Cit did not account for the size of the atom
Dit was known as plum-pudding model
Ethe model was not similar to any observable phenomena
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Question 73
neco2003
An evidence of the wave nature of matter is
ABrowniam motion
BCompton effect
Cdiffraction
Ddiffusion
Ephoto electricity
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Question 74
neco2003
Which of the following properties is NOT exhibited by sound waves?
ADiffraction
Binterference
CPolarisation
DReflection
ERefraction
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Question 75
neco2003
An object is placed 30 cm in front of a concave mirror of focal length 20cm. Calculate the distance between the object and the image.
A90cm
B40cm
C30cm
D20cm
E10cm
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Question 76
neco2003
Lenz’s law of electromagnetic induction states that
Aa force is exerted on a current carrying conductor in a magnetic field
Bthe induced current in a conductor is in such a direction as to oppose the change producing it
Cthe magnitude of the induced electromotive force in a circuit is proportional to the rate of change of the number of lines of force linking the circuit
Dthe magnitude of the induced electromotive force is proportional to the current producing the magnetic flux
Ewhenever there is a change in the magnetic flux linked with the circuit, an electromotive is induced
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Question 77
neco2003
Which of the following statement(s) is/are correct about the isotopes of an elements? They have the same
I. chemical properties
II. nucleon number
III proton number
AI only
BII only
CI and II only
DI and III only
EI,II and III
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Question 78
neco2003
Which of the following statement(s) is/are correct?
I. When a liquid expands its density falls
II. When a mercury-in-glass thermometer is placed in a hot liquid, the mercury level first descends and then rises.
III. The apparent expansion of a liquid is greater than its real expansion.
AI only
BII only
CIII only
DI and II only
EII and III only
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Question 79
neco2003
A ball of mass m moving at velocity u collides with another ball of equal mass at rest. If the two balls move off together after the impact, calculate their common velocity.
A\(\frac{u}{v}\)
B\(\frac{u}{2}\)
Cu
D2u
E\(\frac{u}{m}\)
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Question 80
neco2003
A body is launched from the earth’s surface, of radius R, so that it just escapes from the gravitational influence of the earth; If the gravitational constant is G and the mass of the earth is M, what is the escape velocity of the boby.
A\(\sqrt{2GM}\) ÷ R
B\(\frac{\sqrt{2GM}}{R}\)
C\(\frac{\sqrt{2G}}{MR}\)
D\(\sqrt{2GMR}\)
E\(\frac{\sqrt{R}}{2GM}\)
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Question 81
neco2003
The area under the curve of a velocity time graph represents
Aacceleration
Bdistance covered
Cinstantaneous speed
Dtime taken
Ework done
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Question 82
neco2003
The mode of transference of heat which does not require any material medium is
Aconduction
Bconvection
Cevaporation
Dradiation
Etransmission
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Question 83
neco2003
Which of the following scientists postulated that moving particles exhibit wave properties?
AErnest Rutherford
BErwin Schroedinger
CFrank Hertz
DLouis de Broglie
EWerner Heisenberg.
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Question 84
neco2003
The space surrounding a magnet in which the magnetic force is exerted is
Amagnetic field
Bmagnetic flux
Cmagnetic point
Dmagnetic pole
Emagnetic strength
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Question 85
neco2003
Which of the following statements about the concept of solid friction is NOT true?
AIt always acts in the direction of motion
BIt causes wear and tear in car tyres
CIt depends on the nature of the surfaces in contact
DIt is independent of the area of the surfaces in contact.
EIt reduces the efficiency of the machine
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Question 86
neco2003
In 90 seconds, the mass of a radioactive element reduces to \(\frac{1}{16}\) of its original value. Determine the half- life of the element.
A15.0s
B18.0s
C22.5s
D30.0s
E45.0s
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Question 87
neco2003
The distance between two successive crests of a water wave is 0.5m. If a particle on the surface of the water wave makes two complete vertical oscillations in 1s, calculate the speed of the wave.
A0.25ms-1
B0.50ms-1
C1.00ms-1
D2.00ms-1
E4.00ms-1
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Question 88
neco2003
A transformer is required to give 120V from a 240V mains supply. If the primary has 5500 turns, how many turns has the secondary?
A232
B450
C550
D2750
E11000
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Question 89
neco2003
A short chain is usually attached to the rear side of petro tanker trailing behind it to ensure that the
Acharges generated by friction in the tanker are conducted to the earth
Bchain vibrates in resonance with the tanker’s engine
Cheat generated by friction in the engine is conducted to the earth
Dpetrol tanker is balanced on the road
Etanker does not exceed a certain speed limit
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Question 90
neco2003
Calculate the critical angle for light traveling from water to air. (Refractive index of water = 1.33)
