If two parallel conductors carry currents flowing in the same direction, the conducts will
Aattract each other
Brepel each other
Cboth move in the same direction
Dhave no effect on each other
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Question 852
jamb1994
Which of the following are found in the receiver but not in the microphone of a telephone handset? i. Diaphragm. ii. soft iron pole pieces. iii. permanent magnet. iv.carbon blocks
Ai and ii
Bi and iv
Cii and iii
Diii and iv
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Question 853
jamb1994
Two capacitors R1 = 4\(\Omega\) and R2 = 5\(\Omega\) are connected in parallel across a potential difference. If P1 and P2 represent power dissipated in R 1 and R2 respectively, then the ratio P1 : P2 is
A4 : 5
B5 : 4
C16 : 25
D25 : 16
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Question 854
jamb1994
A capacitor 8\(\mu\)F is charged to a potential difference of 100V. The energy stored by the capacitor is
A1.0 x 104J
B8.0 x 10J
C1.25 x 10J
D4.0 x 10-2J
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Question 855
jamb1994
When a biro pen rubbed on a dry silk cloth is moved very close to a piece of paper on a dry table, the pen is found to pick up the paper. This is because
Aboth the pen and the cloth are magnetized
Bthe pen is magnetized but the cloth is not
Cthe pen is charged while the cloth is magnetized
Dboth the pen and the cloth are charged
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Question 856
jamb1994
Which of the following has the lowest internal resistance when new?
Aleclanche cell
BDaniel cell
CAccumulator
DTorch battery
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Question 857
jamb1994
If the Nigeria flag (green, white, green) is viewed in pure yellow light, which of the following set of colours would be observed on the flag?
AGreen, yellow, green
BRed, yellow, red
Cblack, yellow, black
DGreen, white, green
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Question 858
jamb1994
In a projection lantern of focal length f, the object distance u, is such that
Au > 2f > f
Bu < f < 2f
Cu = f < 2f
Df < u < 2f
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Question 859
jamb1994
An object is placed directly below a glass block of thickness 3.0cm. Calculate the lateral displacement of the object if the refractive index of the glass is 1.5.
A1.0cm
B1.5cm
C2.0cm
D2.5cm
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Question 860
jamb1994
An object is placed in front of a converging lens of a focal length 20cm. The image is virtual and has a magnification of 2. What is the distance of the object from the lens?
A5cm
B10cm
C30cm
D40cm
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Question 861
jamb1994
Light of frequency 6.0 x 10\(^{14}\) Hz travelling in air is transmitted through glass or refractive index 1.5. Calculate the frequency of the light in the glass
A4.0 x 1014Hz
B6.0 x 1014Hz
C7.5 x 1014Hz
D9.0 x 1014Hz
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Question 862
jamb1994
To produce a parallel beam of light from a concave mirror, the distance at a which the lamp should be placed from the mirror is equal to
Athe focal length
Btwo times the focal length
Cthe distance of the image
Dtwo times the radius of curvature
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Question 863
jamb1994
The note produced by a stretched string has a fundamental frequency of 400Hz. If the length of the string is doubled while the tension in the string is increased by a factor of 4, the frequency is
A200Hz
B400Hz
C800Hz
D1600Hz
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Question 864
jamb1994
A pipe of length 45cm is closed at the end. Calculate the fundamental frequency of the sound wave generated in the pipe if the velocity of sound in air is 360ms-1 [Neglect end correction]
A5.5Hz
B148.5Hz
C200.0Hz
D550.0Hz
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Question 865
jamb1994
The fundamental frequency of vibration of a sonometer wire may be halved by
Adoubling the length of the wire
Bdoubling the mass of the wire
Creducing the tension by half
Dreducing the absolute temperature by half
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Question 866
jamb1994
The sound from a source travelled to the bottom of the sea and the echo was heard 4s later. If the speed of sound in sea water is 1500ms-1 the depth of the sea is
A6000m
B3000m
C1500m
D375m
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Question 867
jamb1994
The equation of transverse wave traveling along a string is given by Y = 0.3 sin(0.5x - 50t) where Y and X are in cm and t is in seconds.Find the maximum displacement of the particles from the equilibrium position
A50.0cm
B2.5 cm
C0.5cm
D0.3cm
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Question 868
jamb1994
Two similar kettles containing equal masses of boiling water are placed on a table. If the surface of one is highly polished and the surface of the other is covered with soot, Which of the following observations is correct
AThe two kettles will cool down at the same rate
Bthe polished kettle cools down more quickly by conduction
Cthe kettle covered with soot cools down more quickly because it is a good radiator
Dthe kettle covered with soot cools down more quickly by the process of heat convection
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Question 869
jamb1994
If a room is saturated with water vapour, the temperature of the room must be
Aat 0oC
Babove the dew point
Cat 100oC
Dbelow or at the dew point
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Question 870
jamb1994
Heat is supplied to a test tube containing 100g of ice at its melting point. The ice melts completely in 1 min.What is the power rating of the source of heat? [Latent heat of fusion of ice = 336Jg-1]
