An element of nucleon number P and atomic number Q emits an alpha particle from its nucleus. The resultant numbers of the new element formed are respectively
AP - 4 and Q + 2
BP - 4 and Q - 2
CP + 2 and Q + 2
DP + 2 and Q - 2
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Question 2
waec2014
An aluminum foil is placed across a beam of radiation from a radioactive source. Which of the following types of radiation will be stopped by it?
Aalpha and beta particles
Balpha and gamma particles
Cbeta and gamma particles
Dgamma particles only
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Question 3
waec2014
Which of the following statements is the major advantage of nuclear fusion over nuclear fission?
Anuclear fusion releases more energy
Bmore neutrons are released in fusion than in fission
Cfussion does not release as much dangerous radiation as fission
Dfusion reactions occur more readily than fission
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Question 4
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The energy required to separate the nucleus in an atom completely is known as
Amass defect of the atom
Belectron binding energy
Cexcitation energy
Dnuclear binding energy
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Question 5
waec2014
The circuit above illustrates a standard resistor R, voltage source E and a lamp L connected in series. If the temperature of R is increased, the brightness of the lamp will
Aincrease sharply
Bdecrease slightly
Cremains the same
Dincrease gradually
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Question 6
waec2014
A transformer has 400 turns of wire in the primary coil and 40 turns in the secondary col. If the input voltage is 150 volts. Calculate the magnitude of the output voltage
A150V
B55V
C36V
D15V
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Question 7
waec2014
A wire of length 100 cm has a resistance of 10\(\Omega\). If its cross-sectional area is 0.005cm2, determine its resistivity
A0.0005\(\Omega\)cm
B0.0015\(\Omega\)cm
C0.0016\(\Omega\)cm
D0.0700\(\Omega\)cm
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Question 8
waec2014
In the circuit diagram above, E is a battery of negligible internal resistance. If its emf is 9.0V. Calculate the current in the circuit ``
A1.8A
B1.0A
C0.8A
D0.3A
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Question 9
waec2014
Two identical charges situated 20cm apart in vacuum repel each other with a force of 1.0N.Calculate the value of each other with a force of 1.0N. Calculate the value of each charge. [(14 \(\pi \varepsilon_o)^{-1}\) = 9 x 109Nm2C-2]
A21\(\mu C\)
B3.6\(\mu C\)
C4.0\(\mu C\)
D4.4\(\mu C\)
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Question 10
waec2014
A 15 \(\mu F\) capacitor is connected to a 240V, 50Hz ac. source. Calculate the reactance of the capacitance [\(\pi = 3.142\)]
A16\(\Omega\)
B68\(\Omega\)
C106\(\Omega\)
D212\(\Omega\)
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Question 11
waec2014
An electric motor converts
Aelectrical energy to mechanical energy
Bmechanical energy to electrical energy
Cmechanical energy to chemical energy
Delectrical energy to thermal energy
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Question 12
waec2014
Which of the following conditions occur at resonance in a series RLC circuit? i. Impedance equals resistance ii. Current is maximum iii. Reactance is maximum iv. Current and voltage are 90° out of phase
Ai and ii only
Bi and iii only
Ci, ii and iii only
Di, ii, iii and iv
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Question 13
waec2014
The energy stored in a simple cell is
Aelectrical
Bnuclear
Cthermal
Dchemical
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Question 14
waec2014
In an ac circuit when the supply voltage frequency is equal to the resonant frequency, the current
Aleads the supply voltge by 90o
Blags behind the supply voltage by 90o
Cleads the supply voltage by 45o
Dis in phase with the supply voltage
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Question 15
waec2014
The region around a magnet in which magnetic force can be expressed is known as
Adeclination
Bflux density
Cfield
Dflux
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Question 16
waec2014
An ammeter can be adapted to measure potential difference by using a
Ashunt
Bmultiplier
Crheostat
Dresistance box
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Question 17
waec2014
An object is placed in front of two plane mirrors inclined at 60o to each other. Determine the number of the images formed
A2
B3
C5
D7
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Question 18
waec2014
an observer hears an echo 1.26 seconds after blowing a whistle near a cliff. calculate the distance of the observer from the cliff. [speed of sound in air = 330ms-1]
A104.4m
B207.9m
C415.8m
D523.8m
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Question 19
waec2014
A fish inside a pond appears to be at a depth of 1.5m when viewed vertically from above. The refractive index of the water in the pound is 1.3. Calculate the apparent displacement of the fish
A2.50m
B1.95m
C1.50m
D0.45m
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Question 20
waec2014
The diagram above illustrates an electromagnetic wave travelling with speed 3.0 x 108ms-1. Calculate the wave length of the wave
