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 252
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 253
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 254
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 255
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 256
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 257
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 258
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 259
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 260
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 261
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 262
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 263
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 264
waec2015
All electromagnetic waves in a vacuum have the same
Awavelength
Bfrequency
Cspeed
Damplitude
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Question 265
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 266
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
Cred light is more intense than the blue light
Dblue light is more intense than the red light
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Question 267
waec2015
A girl standing some distance from the cliff claps her hands and hears the echo 0.8s later. calculate her distance from the cliff. [speed of sound in air = 320 ms-1]
A23m
B128m
C288m
D298m
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Question 268
waec2015
When an air column is set into vibrations, the distance between two consecutive nodes of the resultant wave is
Aone quarter of the wavelength
Bhalf of the wavelength
Cthe wavelength
Dtwice the wavelength
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Question 269
waec2015
A swimming pool is 2.1m deep. If it contains water of refractive index 1.3, calculate the apparent depth of pool
A3.4m
B2.7m
C1.6m
D0.8m
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Question 270
waec2015
An object is placed 15cm from a diverging lens of focal length 12cm. The image of the object formed by the lens in
