\(^{226}_{88}Ra\) \(\to\) \(^{222}_{86}Rn\) + X + Energy. The equation above represents a nuclear decay of radium isotope. What is X?
AAlpha particle
BBeta particle
CGamma ray
DNeutron
EX – ray
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Question 1283
neco2003
A wire of length 100cm and cross-sectional area 2.0 × 10-3cm2 has a resistance of 0.10 ω. Calculate its electrical conductivity.
A2.0 × 10-6 ω-1cm-1
B5.0 × 105 ω-1cm-1
C2.0 × 106 ω-1cm-1
D5.0 × 10-6 ω-1cm-1
E5.0 × 107 ω-1cm-1
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Question 1284
neco2003
Lines of force
I. Begin and end on equal and opposite electric charges.
II. are in state of tension which causes them to shorten
III. attract one another.
Which of the statement(s) is/are correct?
AI only
BII only
CIII only
DI and II only
EII and III only
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Question 1285
neco2003
Which of the following radiations have the longest wavelength?
AGamma rays
BInfra-red
CLight waves
DRadio waves
EUltra-violet rays
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Question 1286
neco2003
How much heat is required to convert 50g of water at 100°C to steam at the same temperature? (Specific latent heat of vaporization of water = 2260 Jg-11)
A1.13 × 10-4J
B1.31 × 102J
C1.30 × 104J
D1.13 × 105J
E1.31 × 106J
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Question 1287
neco2003
For which of the following sets are the units fundamental?
AArea, length and volume
BImpulse, mass and time
CLength, time and mass
DVelocity, distance and time
EVolume, mass and density
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Question 1288
neco2003
A machine has an efficiency of 80%. If the machine is required to overcome a load of 60N with a force of 40N, calculate its velocity ratio.
A0.53
B0.83
C1.20
D1.50
E1.88
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Question 1289
neco2003
Calculate the amount of heat generated in an external load of resistance 8Ω if an alternating current of peak value 5 A is passed through it for 100s.
A2.0 × 104J
B1.0 × 104J
C5.0 × 103J
D4.0 × 103J
E2.0 × 102J
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Question 1290
neco2003
Evaporation of a liquid produces cooling of the liquid because the
Aattraction between the vapour molecules and the liquid molecules is great
Baverage kinetic energy of the liquid is reduced
Cdensity of the liquid decreases
Dvapour pressure above the liquid rises
Evolume of the liquid decreases
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Question 1291
neco2003
Which of the following instruments can be used to measure e.m.f. most accurately.
AAmmeter
BGalvanometer
CMetre bridge
DPotentiometer
EVoltmeter
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Question 1292
neco2003
Young’s modulus of elasticity is the ratio of stress to strain, provided the load does not exceed the
Abreaking point
Belastic limit
Cplastic limit
Dstress limit
Eyield point
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Question 1293
waec2003
The bar magnet illustrated in the diagram above picks up an unmagnetised steel nail X. In turn, X picks up a similar nail Y and so on. The nail are said to be magnetised by
Aconduction
Bsingle touch
Cinduction
Ddivided touch
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Question 1294
waec2003
The diagram above shows the resultant electric field pattern due to two electric point charges P and S. Which of the following statements is correct?
AP is negatively charged while S is positively charged
BP is positively charged while S is negatively charged
Cboth P and S are positively charge
Dboth P and Q are negatively charged
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Question 1295
waec2003
Which of the following reactions represents nuclear fusion?
A\(^2_1H + ^2_1H \to ^3_2He + ^1_0n\)
B\(^235_92U + ^1_0n \to ^145_56Ba + ^90_36Kr \)
C\(^234_90TH \to ^0_-1n + ^3_2He + ^1_0Pa\)
D\(^238_92U \to ^4_2H \to ^3_2He + ^234_90Th\)
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Question 1296
waec2003
Nuclear fission is preferred to nuclear fusion in the generation of energy because?
Avery high temperature are required for fusion
Bthe raw material of fusion are not easily obtained
Cenergy obtained from fusion is relatively smaller
Dthe by product of fusion are very dangerous
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Question 1297
waec2003
The minimum energy required to remove an electron from an atom is known as
Aexcitation energy
Bionization energy
Cbinding energy
Dphoton energy
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Question 1298
waec2003
A radioactive element has a decay constant of 0.077s-1, calculate its half life
A12.5s
B9.0s
C5.1s
D0.5s
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Question 1299
waec2003
Which of the following statements is true of ultra violet radiations? It
Asupports the sensation of hearing
Bdoes not cause the emission of electrons from metals
Cis an electromagnetic wave
Dis not capable of causing sun burns
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Question 1300
waec2003
Which of the following statements is not true of the isotopes of an element? They
