Two angles of a pentagon are in the ratio 2:3. The others are 60o each. Calculate the smaller of the two angles
A72o
B100o
C120o
D144o
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Question 2
waec2015
\(^{226}_{88}Ra\) emits two alpha particles to produce polonium(po) nuclide. The correct formula for the nuclide?
A\(^{224}_{86}po\)
B\(^{222}_{86}po\)
C\(^{222}_{84}po\)
D\(^{218}_{84}po\)
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Question 3
waec2015
Which of the following radiations constitutes a stream of electrons?
ARamma rays
BX-rays
CCathode rays
DRadio waves
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Question 4
waec2015
Which of the following statements about diode is correct?
Areverse bias diodes have low resistance
Bforward bias diodes have high resistance
Cforward bias diodes produce high current
Dforward bias diodes function as a result of heat
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Question 5
waec2015
in a nuclear fission process, the mass defect was 1.2 x 10-5kg. Calculate the energy released. [speed of the light in vacuum = c = 3.0 x 108ms-1]
A1.08 x 1011J
B5.20 x 1011J
C1.08 x 1012J
D2.50 x 1013J
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Question 6
waec2015
When current flows through a moving-coil galvanometer, the force exerted on the pointer depends on the: i. strength of the current. ii. magnetic field strength. iii. length of the coil. Which of the statement(s) above is/are correct?
Ai only
Bii only
Ci and iii only
Di, ii and iii
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Question 7
waec2015
What must be connected between the points P and Q to establish a steady current through the incomplete circuit diagram given?
AFuse
Bammeter
CCell
Dvoltmeter
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Question 8
waec2015
The angle which the direction of the earth magnetic field makes with the horizontal at a palace is know as.
Aangle of contact
Bangle of dip
Cangle of declination
Dmagnetic meridian
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Question 9
waec2015
The mass of the earth is 6.0 x 1024kg and that of the moon is 7.0 x 1022kg. If the distance between them is 4.0 x 108m, calculate the force of attraction between them. [G = 6.7 x 10-11Nm2kg-2]
A1.8 x 105N
B1.8 x 1010N
C1.8 x 1015N
D1.8 x 1020N
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Question 10
waec2015
A battery of emf 24V is connected to three resistor P, Q and R as illustrated in the given diagram. Determine the voltage across the resistor Q.
A5V
B10V
C14V
D24V
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Question 11
waec2015
A wire of cross-sectional area 0.60mm2 has a restivity of 7.2 x 10-7 \(\Omega\). Calculate the length of wire that will have a resistance of 3\(\Omega\).
A0.25m
B2.50m
C3.60m
D36.00
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Question 12
waec2015
The symbol illustrated above is that of a resistor?
Awhich absorb light
Bwhich emits light
Cwhich absorbs heat to function properly
Dwhose resistance is light dependent
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Question 13
waec2015
Which of the following statements about a three-pin plug is/are correct. i. The brown wire is the live wire. ii. The fuse is connected to the live wire. iii. The earth wire is coloured blue
Ai only
Bii only
Ci and ii only
Di, ii and iii
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Question 14
waec2015
Which of the following statements is correct? When capacitors of different values are connected in series
Athe same charge flows through them
Bthe same voltage appears across each capacitor
Cdifferent quantities of charges flow through them in different voltages across them
Ddifferent quantities of charges flows through them with the same voltage across them
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Question 15
waec2015
An electric generator rated 12 kW, 2 kV distribute power through a cable of resistance 20\(\Omega\). Calculate the power loss in the cable.
A120 w
B360 w
C720 w
D2400 w
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Question 16
waec2015
An alternating current supply is connected to an electric lamp which lights with the same brightness as it does with direct current source emf 6v. The peak potential difference of the a.c supply is
A4.6v
B6.0v
C8.5v
D12.0v
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Question 17
waec2015
The diagram given illustrates two charged particles W and X. The charges on W and x are respectively
Anegative; negative
Bnegative; positive
Cpositive; positive
Dpositive; negative
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Question 18
waec2015
All electromagnetic waves in a vacuum have the same
Awavelength
Bfrequency
Cspeed
Damplitude
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Question 19
waec2015
An object is placed 20cm from a concave mirror of focal length 15cm. Calculate the linear magnification of the image formed
A0.5
B1.5
C2.0
D3.0
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Question 20
waec2015
Red light travels faster than blue light when both of them pass through a glass prism because the
Arefractive index of red light is grester than that of blue light
Brefractive index of blue light is greater than that of red light
