Which of the following is not part of the electromagnetic spectrum?
ARadio wave
BGamma ray
CInfra-red ray
DAlpha particle
EX-ray.
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Question 1702
waec1996
Which of the following substances is most viscous at room temperature?
AWater
BAlcohol
CPetrol
DPalm oil
EKerosine
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Question 1703
waec1996
What is the decay constant of a radioactive element whose half-life is 3 seconds
A0.132s-1
B0.23s-1
C0.347s-1
D0.693s-1
E0.924s-1
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Question 1704
waec1996
The resistance in a series R-C circuit is 5 Ω. If the impedance of the circuit is 13 Ω, calculate the reactance of the capacitor
A65 Ω
B18 Ω
C16 Ω
D14 Ω
E12 Ω
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Question 1705
waec1996
ln the diagram above, the resistor has a resistance 8 Ω while the reactances of the inductor and the capacitor are 10 Ω and 16 Ω respectively Calculate the current in the circuit
A3.6A
B3.8A
C9.2A
D10.0A
E13.0A
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Question 1706
waec1996
Calculate the amount of heat generated in an external load of resistance 8Ω if an alternating current of peak value 5A is passed through for 100s.
A20,000J
B10,000J
C5,000J
D4,000J
E200J
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Question 1707
waec1996
The electric potential at point P in the diagram above can be expressed as
AQ2/(4πεor2)
BQ/(4πεor2)
CQ/(4πεor)
DQ2/(4πεor2)
EQ/(4πεor) 2
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Question 1708
waec1996
The diagram above illustrates an isolated metal sphere carrying charge W in a medium whose permittivity is so. The magnitude of the electric field intensity at P can be expressed as
AQ2/(4πεor2)
BQ/(4πεor2)
CQ/(4πεor)
DQ2/(4πεor2)
EQ/(4πεor) 2
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Question 1709
waec1996
Soft iron is used in making the armature of an electric bell because it
Aretains its magnetism for a longtime
BLoses its magnetism readily
CProduces permanent magnets
Dis not easily magnetised
Edecreases the magnetic effect of a direct current
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Question 1710
waec1996
A cell of e.m.f. 1.5V is connected in series with a resistor of resistance 39. A high-resistance voltmeter connected across the cell registers only 0.9V. Calculate the internal resistance of the cell
A1.85Ω
B2.0Ω
C2.4Ω
D4.5Ω
E5.0Ω
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Question 1711
waec1996
Lenz's law of electromagnetic induction states that
Ae.m.f. is induced in a circuit whenever there is a change in the magnetic flux linked with the circuit.
Bthe induced current in a conductor is in such a direction as to oppose the change producing it
Cthe magnitude of the induced e.m.f. in a circuit is proportional to the rate of change of the number of lines of force linking the circuit
Da force is exerted on a current-carrying conductor in a magnetic Held
Ethe induced charge is constant for a fixed change of flux.
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Question 1712
waec1996
A wire of length 100cm and cross-sectional area of 2.0 x 10-3cm2 has a resistance of 0.10 Ω. Calculate its electrical conductivity.
A5.0 x 107Ω-1cm-1
B5.0 x 106Ω-1cm-1
C2.0 x 106Ω-1cm-1
D5.0 x 105Ω-1cm-1
E2.0 x 106Ω-1cm-1
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Question 1713
waec1996
The diagram above illustrates the conversion of a galvanometer of resistance 29 to an ammeter. The galvanometer gives a full-scale deflection for a current of 10mA. Calculate the value of R.
A2.0 x 103 Ω
B2.0 x 102 Ω
C2.0 x 10-1 Ω
D2.0 x 10-2 Ω
E2.0 x 10-3 Ω
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Question 1714
waec1996
Which of the following is not a component of a d.c. electric motor?
ACommutator
BField magnets
CSlip rings
DArmature
ECarbon brushes
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Question 1715
waec1996
The main function of the mouth of a telephone is to convert sound energy into
Aheat energy
Blight energy
Cchemical energy
Delectrical energy
Emechanical energy
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Question 1716
waec1996
CalcuIate the power delivered by a 3-phase line if its voltage and current at 132KV and 60A respectively.
A2.38 x 107W
B7.92 x 106W
C3.96 x 106W
D2.64 x 106W
E7.92 x 104W
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Question 1717
waec1996
The diagram above represents a stationary wave set up in a string which is fixed at both ends. lf the frequency of the wave is 256Hz and the distance N1 N2 equals 1.5m, calculate the speed of the wave.
A128ms-1
B192ms-1
C384ms-1
D768ms-1
E1536ms-1
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Question 1718
waec1996
The diagram above illustrates a variation of the displacement y of a wave particle with time t. lf the velocity of wave is 250ms-1, calculate the distance between two successive particles which are in phase
A20m
B2.5m
C3.0m
D5.0m
E50.0m
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Question 1719
waec1996
The speed of sound in air is 330ms-1. How far from the centre of a storm is an observer who hears a thunder clap 2s after the lightning flash? (Neglect the time taken by light to travel to the observer)
A1320m
B165m
C600m
D330m
E343m
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Question 1720
waec1996
A sound wave of velocity 350 ms-1 is directed towards the surface of water. lf the ratio of the wavelength of sound in water to that in air is 425:100, calculate the velocity on the wave in water
